Alright,
So this is probably not gonna be the magic pill that will make all the crash problems go away. It worked in my case.
Changed my Display mode from Fullscreen to Windowed ( Fullscreen ) and have not had a single crash for the past 2 days no matter how many ballgroups or zergs were around. ( Playing PC EU Grayhost during peak time. )
It's easy thing to check, so maybe it will help some of you guys as well.
I got nothing for lag and rubber banding though. Still suffering from that lmao.
Good luck.