You buy forge points by clicking on the + sign at the end of the FP bar on the top center of the screen.
Invite players by clicking on the friends tab on the social bar at the bottom of the screen. Then click on the Find button. This brings up a new window with tabs one of which is invite player.
Well, in my main city I have 233 of which 87 are female, 4 are indeterminate, and 142 are male. These are as I see them, but some are pretty close and could go either way.
It's my impression that lately the events have been pretty even. And the castle seems to be pretty even although with one...
I am okay with the idea, but I don't really see much need for it.
Other than event buildings I mostly upgrade those buildings that provide A/D boosts. And I always go to the Town Hall to see how many of those there are.
I usually bump by 1000 (sometimes more) when I'm bidding at the last minute.
Usually though I can't wait around for the end so I just stick in a first bid that I think is high enough and I'm happy to pay if I win.
Auto battle frequently targets closest threat especially if it can strike the on it's next turn. Auto battle usually moves units forward as fast and far as possible.
In your case the cavalry unit moves first and moves much further than the rogues. It presents an immediate threat and is taken...
Yeah that's a risk you take. That's why I seldom put FPs on buildings unless they are at least halfway (preferably 80%) to leveling up.
You could finish off the level yourself, maybe with some help from other contributors.