believe it or not i compress on sub groups as well as the two bus, im using the waves api 2500 religiously for this, brilliant compressor !! The internal sidechaining and knee settings allow me to get away with that, wat i mean is using compressors on subgroups as well as two bus can be a bit ott in some case, or most tbh

I occasionally do the same thing if the mix calls for it; e.g., drum bus compression, guitar bus compression, etc., for "character".  Those go into the master bus (or exported version) which also uses compression, though usually more transparent types in most cases. 

the waves api 2500 isnt really colourful anyway

I was having the same problem until I noticed Ozone has a History Depth setting that can range from 50 to Unlimited.  When I lowered it to 50 the problem seemed to go away.  Don't know why it would - it's just a list of changes, but it made a difference.

If you are self-mastering, "mastering" is simply adding some additional plugin(s).  Period.
 
I do all my "tracking" at the lowest latency (smallest buffer) I can run at. 
 
When I've got all my tracks down, then I increase my hardware buffers to 1024, and do my "mixing" by adding various effects as necessary. 
 
When I've beat that horse to death, then I focus on the "Master Out Bus" by inserting whatever plugin I find necessary on that bus.  I call that "mastering".
 
I don't see the need to PRETEND that now I'm a recording musician, and now I am a mixing engineer, and now I'm working in a mastering suite on some stereo wave file some client sent me via email.  Like most of you, I am one guy trying to create "art".  If I get the level up to K-12 and hear some kind of crap I didn't hear before, I'm damn well going back in the mix and fix it.  After all that work, and blisters on my fingers, it seems crazy to think it somehow irreligious not to make the final product the best that you possibly can!!!!