Ill be honest here. Your heart is in the right place (balance), but you are not thinking clearly when it comes to the overall balance.
You want to break the meta, i get that, but with how you've built this game all you are going to do is make a new meta, and everything will get nerfed until its useless. Thats not balance, but breaking your own game.
People will like what is fun for them, and 9 out of 10 times that makes a meta. If you can't explain it, you can't predict it. Then something somewhere else is broken and needs looked into.
With how you've made this game, there will always be a meta. Yes, there will be some players that will find a way to break it, but in the end it will always come back to that.
I personally believe its in the numerous damage types that you offer, that causes the meta builds. Yes that lends to challenges when figuring out what you need, but it creates the original meta. Grineer/corrosive-heat/slash-viral, Corpus/gas-magnetic/electric-radiation, Infested/gas-radation/slash,
Follow this meta let's you do the most damage quickly, especial with how (in my opinion) broken enemy scaling is.