Well, that may depend of the agenda of each miner, most of them are there just for profit, So i don't see them attaking the network or something like that.

They may monopolize the blockchain yes!. Thay may let a lot of other miner's blocks orphan, well yes a 51% can do that..

But a 51% can't move balance for one wallet to another without having those wallet's privatekeys, they can't create more coints than the mined coins limit, they can't change the consesus rules or anything like that.

I'm not an expert, i know that 51% "attack" is bad, but is not the worse right? I think that there should be a topic for that more detailed, please if somebody have that link put it here.

Regards!