1) I think a prestige system would be a lot better. With the old system, once you reached level 70, you could buy all the items. This meant level 71-150 were kind of pointless (aside from the motivation given to reach the higher levels).
Prestige could take you back to level 5, let you keep all your items for when you get to level 30 again, but have a different icon for your level to show off how far prestige
2) I originally thought this is how the fusion system would work
or at least mix figures together when you fused say 2 weapons together. I prefer the current system though, it allows you to keep on fusing continuasly so you can work on that even once you've found your builds.
3) Disagree. The current system is cool. If you have a heat shield it's better to buy energy weapons. Energy shield and heat weapons are easier
Means mechs can be countered so not just one build is the best build
4) How would you propose to do this?