I am sure this has been talked about before, so I hope I am not really way out in left field. So often I am swimming upstream only to find that Sonar has a solution I missed. But anyway here is my approach to volume automation.
 
I (like many others) like to use the volume envelope to fine tune each phrase of a track when I am getting the final mix ready. I bring up the quiet parts and lower the loud parts. Especially on vocals.
 
But the problem is that later on, I need to adjust the track's volume overall, and leave the fine tuning in place on a relative basis.
 
In the past, I would route the track to a bus and use the bus volume. This works OK but adds a seemingly extra bus.
 
Also, I am aware that if you know what you are doing, you can click on the whole track and make the volume envelope go up or down for the whole track. But this does not seem intuitive. I prefer a fader or knob.
 
And automating  the gain control is an option but it does not work in a linear fashion if you have any kind of compression.
 
Today I started experimenting with using another approach. I figured I could automate the output of a plug that has no other function except volume. This would add an automated "volume" control before the volume fader for the track.
 
First I tried automating the output of an EQ filter set to flat, so that only the output level was processed.  This worked, but left me thinking that the plug was churning CPU cycles.
 
Then I discovered a seemingly useless DirectX plug left over from my Sony Movie Studio 13 that only has a volume slider. It is called "Volume". The only function it has is volume control. And Sonar can easily automate it.
 
So now I can insert this plug at the end of the effects chain for a track, and automate the volume.  Then I can use the normal Sonar volume fader as an overall control.
 
And if I move the volume plug from the end of the effects chain to other places, I can keep the envelopes I have created. So for instance, if I have a compressor in an effects bin, and I add the volume plug after the compressor, it will be an automated volume control. If on the other hand I move it before the compressor, it will be an automated compression level control (when combined with the gain control).
 
It is not necessary to use the so called "volume" plug from Sony.  Any plug that can be disabled except for output level will work.
 
 
 
 
 
 
 
 
 
 
 
 

The built-in way of handling this is to enable Offset mode in the Mix module, which allows you to set an offset that the automation will ride on top of. The shortcut for this used to be "O", but it was too easy to enable it inadvertently and not notice the little plus signs on widgets indicating Offset mode.
 
After you've set the offset value, disable Offset mode (i.e. return to Envelope mode) to continue mixing.

I usually try Gain first and if that's not enough I'll edit the Node values.
 
I've tried Offset, I think every fader moved the last time I tried it, or every fader on tracks with automation did.  I need to double check that though.  I know that deleting an Automation Lane does not remove the automation.  I have to disable the Read, and even then the Automation icon remains on the track just above the fader.
 
I have a few problem reports I should submit I guess.

OK! perfect, the offset mode. I have to come down from the hills more often.
 
BTW, I found an article on Mix Online talking about the recording of Dobie Gray's Drift away. 
 
Reminds me of the old days when I had a Fostex 8 track and I would put different instruments on the same track and then have to do a very dynamic mix to compensate:
 
Williams (writer and producer), not wanting to add any additional timbre to Gray's sonorous vocal, had the singer harmonize with himself, despite the fact that tracks were becoming scarce. “We had to put some of the harmony tracks onto the parts of the guitar tracks where the guitars were laying out,” says Williams. “We had a piece of one of them on a cymbal track.” The track becomes a bit denser toward the end: A tambourine appears on the ride-out only, and hand-claps were added in the final breakdown chorus.
 
Strings were recorded after tracking was complete in Quadrafonic's wood-paneled front room, recorded by (engineer) (Gene) Eichelberger with a combination of U87s and 224Es and mixed to stereo. “I always made sure I checked them for phase before I recorded them,” he says.
 
This, of course, all went down during the era before console automation, so the mix was physically strenuous. “It took two sets of hands, mine and Gene's, to get that mix done,” says Williams. “There was a lot of riding the faders because of the vocals that were sharing guitar tracks, and a lot of panning for the same reason: We had to put the harmony tracks down the middle in the choruses and then quickly pan the guitars back to hard-left and -right. There was also a lot of muting; for the entire intro and first verse, most of the tracks are muted to reduce noise.” Eichelberger had an unusual trick that grouped mutes — sort of. “We would put three or four cassette boxes together with gaffer's tape and use them to cover several mute buttons at the same time with one hand,” he explains. “That was the ‘master’ mute.” The record got its finishing touch from mastering engineer Bernie Grundman in Hollywood.
 

Dual post, sorry.

I often use clip gain envelopes for evening out dynamics in performance. This sounds natural to me and will generally help to get a more even tone from the compressor. It also lets me use the volume envelope purely for arrangement issues. If you need to constantly heavily ride the volume fader you could also reconsider your arrangement or EQ/pan setup. Another option is splitting those parts to separate tracks (like vox chorus and vox verse) and routing those to the same bus.

Offset mode is great for small corrections but relying on it too heavily early on can create problems later.

Finally, like you said, a separate plug with its own volume can be helpful. I use Vocal Rider for this often.

Sanderxpander


Finally, like you said, a separate plug with its own volume can be helpful. I use Vocal Rider for this often.

I bought Vocal Rider ( and Bass Rider) when they were on sale and was very excited. But after trying them on several projects I find they really don't help so much. I still need to do my compensations by hand.
 
 

Clip gain envelopes are a good idea, but why did Sonar not allow track gain envelope?
 
Vocal Ryder doesn't work for me because it is in real time, and I want to go phrase by phrase off line. Of course you can have Vocal Ryder create an envelope, and then edit it. But when I tried it I lost about an hour out of my life trying to figure out how to make it all work.
 
Now that I am experimenting, I discovered that you can edit the dynamics in V-Vocal, in a very easy to get along with fashion.  I only used it for pitch correction in the past.
 
I uninstalled my copy of Melodyne, but I am certain you could do this kind of work in Melodyne also.
 
When I get more time to experiment, I will try using the Sonar loop construction. This might be the best of all. You double click on the clip, then you can look at the gain envelope with everything all nice and pre-sliced. It is very easy to adjust each phrase level. The only problem for me is I don't use the loop construction enough to really understand it, so the timing is thrown off. I am sure I could figure it out. There are probably a dozen instructions available on this.
 
These off line approaches are great for lead vocals or bass guitar, but when I edit the back up singers I need to see all of the parts at one time.  For instance, to cut off the end of a do-wop style ohhh or ahhhh. My experience is that each take will have a different ending time, and I need to adjust each track to  stop at the same point.
 
So for editing the dynamics of the chorus I will be using envelopes.
 

It is possible to control track gain with an envelop; it requires an additional MIDI track and a virtual MIDI cable. I just tried it with LoopBe1. Here were the steps.

1. On an existing audio track right-click the gain knob in the Inspector, select "Remote Control"
2. In the Remote Control dialog select Controller and set the value to 1, click OK to close
3. Create a MIDI track, set the output to "LoopBe1 Internal MIDI"
4. Add an automation lane to MIDI track and from the drop down in the automation lane, select MIDI
5. Click OK in the MIDI dialog to set the automation lane for 1-Modulation

 
Now everything is set to control track gain with an envelop in the MIDI track automation lane.
 
I think it is easier to add an empty FX Chain at the top of the FX bin and use it as a track gain but the above solution does make the build in track gain available for automation.
 
 
 

I usually let Vocal Rider write its own "opinion" based on my settings, then switch to read mode and make small adjustments where necessary. As for syncing up vocals, have you tried the new vocal sync function? It's made specifically for that.

Oh and yes Melodyne works well for dynamic adjustments too. Not so much for syncing for the reasons you stated.