Without massive investments in ASIC's you have effectively zero influence. Until you have 51% of the hash power you can't make any changes as you simply get ignored unless you follow the exact same rules as the majority.
This is exactly their point. This applies to everyone and all organizational entities.
Think some underestimate firstmover advantage and end-user inertia.
This is a common misconception about bitcoin. Every single node on the network validates every single block, not just miners.
Being able to fake blocks isn't significantly more useful than being able to double spend. I don't see why that would be the tipping point.
The reason you don't see these attacks is that they are difficult and very expensive and they would ruin the value of the coin so you can't even profit off it.
You still have freedom to pick the rules to a small degree though - you choose which blockchain to use. Don't like bitcoin? Try bitcoin cash/ethereum/ethereum classic/litecoin/dogecoin/Monero/siacoin/decred/etc etc.
A common misconception is that miners can pick the rules, but they can't. They can only choose to enforce additional rules (which is powerful), they can't ever violate the original rules.