The Maxim should cost 240 MP, for a start. Its current 260 is unwarranted.
Unless there's something I'm overlooking.
No, the Maxim definitely should not be buffed. Everything has to be done to prevent Maxim spam from becoming a thing again. It's already pretty commonly used in 3v3/4v4 and is a strong strategy despite the individually poor performance of the Maxim. There are way too many lane maps like Whiteball Express, Redball Express etc. that just make it WAY too easy to lock down the entire map with MGs.