I have rented apartments with illegal clauses in the rental agreements. One silly landlord tried to enforce one (cleaning deposit in California), I took her to court, and won.
The point isn't that the clause was illegal so much as it was unenforceable, and the same applies to silly clauses in EULAs. The only real enforcement the manufacturer has is to not honor a warranty if they can find a reason to show you have abused their product. In practice, the clauses you cite are as unenforceable in every practical aspect as the truly illegal rental clause the landlord tried to enforce on me.
I don't like flash, but I use it without having read the EULA, and I don't care what nonsense they have put in there. There is nothing they can put in the EULA that has any affect on me.