I posted some AC tweaks here:
http://mwomercs.com/...istic-tweaking/
Mind you, they look brutal, but the results might be exactly what we need to balance them. Take a look and leave feedback

- less "brutal" groupfire combos (e.g. dual UAC20)
- higher aiming skill required to land all shots to keep up dps (like AC2s already)
- less range for the big-hit weapons seperating sniping from brawling.
- bigger differences between LBX, AC and UACs.
- no obvious "best" weapon (free choice and no "META")
About JJs:
I thought about possible numbers for the JJ fuel and speed.
currently the fuel is independent of number of JJs as is the regeneration, only the thrust seems better, right?
With aiming for between 3 and 5 JJ as the norm, here are my values for how I imagine a good solution.
New JJ:
Each new JJ gives + 10% more fuel and 20% more reload speed, but the lower number of JJs will be less than what we have now.
Fuel of 1 new JJ = about 70% of fuel of 1 old JJ
Reload of 1 new JJ = about 40% of reload speed of 1 old JJ
Fuel of 2 new JJ = 80% fuel
Reload of 2 new JJ = 60% reload speed
Fuel of 3 new JJ = 90% fuel
Reload of 3 new JJ = 80% reload speed.
Fuel of 4 new JJ = 100% fuel
Reload of 4 new JJ = 100% reload speed.
Fuel of 5 new JJ = 110% fuel
Reload of 5 new JJ = 120% reload speed.
For a 12JJ spider:
Fuel of 12 JJ = 180% fuel
Reload of 12 JJ = 280% reload speed.
The 12JJ Spider would have nearly double the fuel and reloads about tripple as of now, but because of the larger fuel tank, it would be only slightly faster overall.
As you can see, 4 JJ would be what we have now, but some mechs like the HGN and Vic don't have more than 3 JJ slots so they will jump a little less even with 3/3 JJs. (just a little)

Obviously you could add one of these % numbers as heat too.