A single note, drum hit, or drum sound in a "masterpiece" by "Mr. or Mrs. Master" is usually boring, dull, nothing particularly special. As a part of the whole song, though, it often fits perfectly. It usually is not meant to be heard alone, nor with prejudice. Sometimes it's great to think as the composer/producer. A lot of times, it's even better to think as a listener who doesn't know what you know, expect what you expect, and question what you question. I've known people who it took years and years and years for them to realize this, and they are still workin' on this. It's part of the "burden" of making music. But the sooner realized, the better.
Sometimes, you just got to leave stuff alone, "give up", move on, and just make some music. Just my 3 cents...
Oh yeah... to answer some of your questions...
Use whatever feels right "1 drum kit" "2 drum kits" "1 drum kit with 2 extra sounds", etc... by try to gel everything together so it doesn't like "new drum sounds for no reason whatsoever"...try having a rhythm going, then going through, in real time, 20-300 "drum kits" until one of those kits maybe fits your rhythm better ************ (sometimes this "randomness" of bank/program changing (after you have your rhythm or melody programmed already) is THE SOLUTION to a lot of sonic problems)*********** .... sometimes, a sound just needs to be changed..... try playing melodies with drum kits, and rhythms with "sounds"
Panning? Think of panning drums (as a start point) like you would a real kit (for example, kick in the middle, snare 12% right, hat 1 15% left, hat 2 19% left, stick 18% right, etc...) .... in general, kicks always down the middle, and snares don't go too far off to the sides. rules are meant to be broken, though.
Read up on frequency cuts for bass kicks and basslines, no they mix and gel together, and don't interfere with each other
Can't think of any tutorials for frequency/panning off hand (not at home right now-- maybe someone else can help out on this), but here's a link to a chart that might grab your attention:
http://digitalprosound.digitalmedianet. ... inter=true
This level of thinking will get you on track, tune your ear, and understand more about what you do and don't understand