I don't think it's that big of a number really, since a large percentage of 3.9% will go towards growing/benefitting the coin. Which is something people these days demand and expect, without thinking of the cost.
Correct. Everyone will get less PoW coins because of PoS blocks. Including dev/fund. It does not change the overall percentage what they get. Dev fund will control 3.91% of all coins minus the ones they are giving away or selling.
That's quite a percentage....