I like that the mechs are being restricted based on what the chassis looks like.  There are certainly enough mechs in the game to find something in your price range with the right missile or ballistic/energy placement to customize your mech how you want.  I strongly dislike squaring off against a mech that is obviously designed to carry a lot of direct fire weapons and then have it end up being a missile boat, it starts to break emersion for me.

Landros, check out Renegade Tech http://www.fluency.paintedtarget.org/rtech/ it uses the FASA template weapons and widowing armor rules made famous in Renegade Legion and Crimson Skies for Battletech.  I find it infinitely more interesting to play that normal battletech since certain weapon combos work extremely well together, like an AC/10 and PPC, or LRMs and SRMS, or, AC/20 + Gauss Rifle.  It really matters which weapon you fire in what order.

As for the 7 PPC mech, yeah, I did that in MW2 also.  The key was to just chain fire the things and make a wall of PPC fuzzies that the target couldn't avoid.  Heat buildup was actually minimal firing in chain mode, but the ludicrous thing was that the PPCs had unlimited range.  If you could catch an enemy on radar and then line up with it and back up until it was off your scope you could still blow it apart and generally the AI wouldn't react since it couldn't detect any enemies to go after.