Try to use transient designer on snare to add more sustain, also you could try to use parallel compression for snare, kick and toms....just use really hard compression with long release, 1176 style comp in all buttons mode for example, and add it as much as you need...
You may use max bass plugin for low end of your kick but be gentle with this, you risking to get too boomy sound if overdo it.
Try to separate you bass guitar into two tracks, one for low end and another one for everything else. In this case you can control it much better and you can add some distortion on the second track (if needed) but keep your low end clean.
Also be sure that you used high-pass filter on each of instruments (before compressor) according to they workable frequencies. Even if you don't hear something, all your compressors feel this.
If all instruments playing at the same time with orchestral elements you can feel free to cut off all from 300 Hz and lower, or even more. If you have some places where orchestrations stay alone or all your guitars and drums plays not so tight, you can bypass this filter by automating.
