All-star is pretty solid as is, no increase is really needed to penalize him or push him further. Certain variants depending on the map can be mildly problematic, i.e. 5th point moonbase z with wrestling can be difficult due to his slow-firerate across a variety of obstacles and plants usually attacking from more long-range. However, his mid-range damage, lane pressure/denial, and large health help to provide great offensive capabilities outside of his three unique triggers. It is unfortunate, but people will usually take the easiest option given to them; imp-punt deals damage quickly and because the all-star needs a way to support/alternate between suppression fire while dealing with characters who have strong defensive skills. I have gone and won matches successfully where I do not use imp punt/long bomb, but I will overheat more often and have to plan when to use the other two abilities to prevent it. An easy way to counter all-stars if they are ability spamming: is to bait them into wasting them, either by staying far or circling them within mid/close range .