Weight has always been bugging me a lot, and it seems to do the same for other people, so I want to suggest some sort of:

A) An anti-gravity module to put on a mech that reduces the weight of the mech (or the torso at least) by 5 - 10%, or

B) A weight upgrade that adds 10 - 100 kg to your mech.

Just my suggestions. Seriously, 1000 kg is a bit too small for a weight limit.

Thats why there are 6 mech slots

Make 2 mechs with 3 good weapons instead of 1 with 6 weapon

Well, some people {including me } battle 1v1 instead of 2v2 or 3v3, but I can see your point.