Are using a compressor on the way in, or after, or is it totally clean. If it's totally clean, it will sound quieter than produced recordings.

Sonar's ( and all DAW's I've used) mixer looks and works about the same as any real mixing desk. I can understand you being overwelmed by a lot of extra controls but really, they are there for good reason. Plus, you are the one who puts them there. 
If I start a new project it's like blank. I have to add any tracks or Busses.  The only channel strips in the mixer are the Audio interface outputs which are by default at unity and can be ignored. I then have to add the Master buss and any effect busses. I can save this as a template for future use. The extra master outs for your audio interface are there to let you know your signal is being sent out to say, 1/2 or 3/4 etc. You certainly need to make sure they are not clipping, but in a properly set up signal chain they should show the same level as your Master Buss. I minimize them and push them out of view. 
 
Which by the way, the Master buss is super important. Sure you can adjust your main output without it but that's certainly not the way 99% of us roll. 
If your mixes are whimpy it's time to bone up on signal chain and how the sound travels from point a to point b. 1,000 of tutorials on the subject, start reading and watching videos. 
 
 

I didn't put all those controls there, They are there by default. I don't need all those bells and whistles, I just want a basic mixer, for two tracks and a main out. I don't need a preview, metronome buss, master buss, or Pro Channel busses.
 
My mixes were whimpy because I didn't see all the level settings of all the meters in the audio chain. Once I did, and adjusted it, the levels came up to normal. Seriously, how many level meters do you have to have ?? Don't believe me ?? Try importing a two track mix, then go into your default mixer and you'll see 9 different level meters, it's ridiculous.

If you wanted to start completely clean. Ignore the start screen. Choose File>New. Then from the template pop up box,
-- blank project --
Completely empty, you don't even have to name it.

Interesting.

It's really quite simple:
 
All Tracks > Master buss > Interface/Main Outs
 
Make sure your Master Buss and Main Outs are set to 0dB

You forgot, Preview buss, Pro Channel buss, Metronome buss, Master buss...

Your using a template that you don't like. Don't use it. Make your own like I said.
And what Kamikaze said is how you start. I don't use the start screen either. 
 
Once you make some custom tracks you save them as Track Templates. 
So it's fast to populate a blank project with your own stuff the way YOU want it. 
 
 

djwayne
You forgot, Preview buss, Pro Channel buss, Metronome buss, Master buss...

I didn't forget them because *I* don't use them 
 
As said above, if you don't want them in your default template, CHANGE the template
 
OR, start all your projects from a BLANK template and add whatever busses you want.

I don't use them either but they are part of the mixer default set up, and they must be dealt with. Either delete them or start fresh. Either way a time consuming road block.