If you want the best standalone try to find a used Radar 24. They sound great and can be had for less then $5k. Then you can import those tracks into any DAW for mixing. I use Reaper. It's cheap and works better then any other DAW I've tried.
I could be mistaken but I believe VST latency is more about the processing power of the computer and the efficiency of the VST plugs. You might get some better help in the keyboard forum.
Your entire mixing process seems apt to cause a lot of problems. Don't set EQ and effects based on a track being soloed. It's how it sounds with everything else that matters.
Reading the other posts, if you are doing a lot of serious cuts between 80hz-3khz that is why. That is where 95% of the most important frequencies live.
I find that simple limiters usually work better on drums then compressors. Compressors are good for softening and evening out a track but limiters are best for taming peaks and keeping the impact.
Bass tracks usually need a lot of compression to sit well in the mix. Try a slow attack and release and then slam it into a limiter. Often that will help give you a better balance and tame those big low end spikes. Just listen carefully for unwanted distortion on the compressors.
The best compromise seems to be 24bits @ 48khz. It usually won't choke your computer and it gives you good quality.
The reason higher sampling rates are preferred is because the computer can process the tracks with fewer rounding artifacts. In other words, the more decimal places a number...
Nowadays there two kinds of home recordists with lots of rack gear. Those that bought it before plug-ins became cheap and those that saw the racks of the first group. :p
In all honesty the stuff you have is good for live use but I wouldn't run any recorded signal through it.
In my experience the most important stuff is at the beginning of the chain and you should upgrade starting at the front and work back.
The chain being:
Performer-instrument-room-mic-preamp/processors-convertor-recorder.
In other words if you are a shitty player playing on shitty gear then no...
There are many ways to treat it but it depends on your budget. The easy way, like bpape suggested, is to run a clowd along the length of the peak and then put up some panels along the angled ceiling.
You could also hang a bunch of baffles and put in a cloth ceiling to hide them or some...
It could just be the powered speakers. What are your monitors? All power amps make noise when turned up and cheap ones make more noise.
When guitars are too close to a video monitor they usually make more of a high pitched buzzing sound. To see if that is the cause just turn off your video...