Does the modified number of players (from using more than one expansion board) affect the number of gate trophies needed to win by closing all gates?

(I know it affects the monster limit and outskirt limit, but not the final battle # of successes to remove a doom token.)

Yes, it affects EVERYTHING except # of successes to remove a doom token during final combat.

It even affects rumors that "recharge" based on the number of investigators, like Mad Bomber, Riots, and Mistrust. The multi-board handicap can be extremely helpful in these cases.

It does not affect the number of successes to remove on doom token? Is this something that was changed with an expansion? Because I'm pretty sure in the core-rules it is stated that the number of successes needed is equal to the number of investigators.

That's what I meant. The board handicap does not lower the number of successes needed to remove a doom token. With 6 investigators using all three expansion boards, you count all mechanics as though there was 4 investigators. Except, you still need 6 successes to remove a doom token.

A bit off topic, but the question is answered and I was wondering- has anyone tried to play with all expansions with 10 players? seems to me the game would be way too easy (and final battle way too hard but with 10 investigators I doubt there will ever be a final battle)

Nobody's logged a 10-investigator game on the stats page (nearly 4000 entries) and there's been only one entry of a 9-investigator game. I don't think anyone's cared to try.

Not to mention, there's only enough skill sliders for 8 investigators :-O

Yeah, I know that, but if someone really wanted to play with 9-10 he can always another token instead of skill sliders

I saw pics of someone who'd forgotten the tokens box who used paper clips instead of sliders. That was a clever idea.

You know, assuming you have paper clips on hand.

I find it amazing how often common office supplies can be helpful in this game.