Maybe you need to look at compressing elements in the mix rather than the mix as a whole, you really want the unprocessed mix to be as fat as possible. If you ever get tunes picked up they will want it unprocessed.By the sounds of it your are using settings that would more heavily compress your master. Watching a seminar on mastering, it was suggested that a ratio of 1.2 to 1 was more than enough, with minimal reduction. Also if you mix into a compressor, every little change you make probably requires that you go in and have to tweak your settings on the pressor. If you just want to make it louder while mixing, use a gain plugin to make up the difference between your peak and 0db. Let your meters tell you where you peak is, and push it enough so that the peak is -1, and still in the clean zone, with 0db reduction from any limiters.
Volume can and does mess with me, leading me to be pretty anal(giggity) about listening to the mixdown at all sorts of different volume levels, before I commit to it.
I know guidelines are frowned upon in some ways, I picked up a tip from a fracture video, he says to get your peak for your drums, then mix in your bass, and you should be adding roughly 3db to your peak level, so if your drums are hitting at -10db, when you mix in the bass, a rough idea is to have the meters hitting -7 with the bass mixed in. I find it a good guideline to follow, but then yur tweak it to fit better from that point. Helped me tremendously, as before I would mix with just ears, and I was way off.
Also for your bass, I can be quite brutal, but iit always help the drums poke out a bit more, I just put in a steep notch into the bass, wherever the kick and snare are hitting.