Could be wrong but the way they phrase it in the movie is like how he asked for health....other people's payments were to give her power. So it was less about a real second wish and him personally giving her power like how he was getting health back.
No.
It was explained that "It grants you a wish, but takes your most valued possession." It's not a "pick and choose" scenario. Max also doesn't get to dictate how that power changes. The Dreamstone still works as it's supposed to. The only thing that changed is that he is now the vessel instead of the gem. They also went out of their way to clarify the "one wish" deal when Max was looking to head to the US President. He specifically says to the person "Can't use you, you've already made a wish".
The rules only changed when it was convenient for the plot (Barbara gets 2nd wish, broadcast signals counts as touching, gaining health off wishes, etc. etc.) which is why it's such a confusing point of discussion.
Every Super hero film has loopholes BS....like how Dr Strange says there is only one way to beat Thanos...really? Ohh the top of my head I can think of a few ways they just win without letting him get the stone.
1) Use a Portal and tell Wong to transfer Vision out of Wakanda once the fighting starts
2) Use a Portal and cut off Thanos hand and the gauntlet
3) Use a Portal and cut Thanos in half
4) Portal in more hero's to fight Thanos and take the Gauntlet
5) seeing how Peter is in raged either Portal him away after he has done his part or some other way get him to leave and get the Gauntlet off his hand
Once you have magic...nothing nothing makes sense
In BVS how the hell does Lex know Zod's DNA will make Doomsday? How does he know it will fight him if he makes a monster? Also who the hell calls there mother by there first name? Super hero films are all stupid fun
Those aren't loopholes.... We can do that game with any film. If Wonder Woman had stopped the robbers in the mall...there'd be no film... yada yada yada
And BvS is just as bad - but we're talking about WW... You gotta stop that "What about this?" I'm glad you liked the film, and it doesn't bother me that you did. There are movies I like that people think are bad. It's ok - I can at least see why they saw those flaws.