Just mute the music in the in game settings.
As for fps, unfortuneatly, the best i can suggest is to choose the lowest settings in the game details possible.
Best bet is to use a new PC 1.7 ghz and above with XP, you would have a much better time I believe.

Alternatively you could switch from Battlepack to the DOS version; there, is a major difference in fps on old comps between Battlepack and non enhanced versions of MechWarrior 2.
I will dig around the old usenet posts to see if I can find anything for the Titanium/Battlepack series, but I do not expect to find much.
Sorry!
Edit:
Almost forgot, if you have not
patched the Battlepack version you may want to consider doing so.
Update:
Scott (alt.games.mechwarrior2)
Apr 14 1998, 12:00 am
For all those stuck in the same boat as me-
The easiest way to double your frame rate is to shut off the
"enemy" cam. Hitting "F4" twice at the beginning of every mission is
what you need to do!
Doc (alt.games.mechwarrior2)
Apr 18 1998, 12:00 am
it worked
I go from single digets up into the 20's
Also learned if I shut off my wireframe on bottom right I gain even more
I get an average of 32 fps in battle
thanks alot
Doc
Anyway, the general consensus for old computers using the Battlepack is this:
Stephen Strangways
Executive Director, Remembrance Compilation Project
Email: R...@mindless.com
I recently purchased the MechWarrior 2 BattlePack. When I started it up,
I got a horrible frame rate. II can only get about 15fps if I run it in
320x240, turn all options to LOW or OFF, and use enhanced imaging all the
time. I have a Pentium 133 with 32MB of RAM. Why the heck is the frame
rate so darn low?