Ask for Help & React to Curses

[lukiluck]

Hello :)

Played some Munchkin recently and two questions came up:

1) The rules state, that I can can only ask for help in combat, when I am not beating the monster on my own, right? When is that checked? Only at the beginning of combat or throughout the whole combat?
Example: I have a fighting power of 10 and I am kicking to door open finding a lvl 9 Monster. That means I am stronger, therefore I can't ask for help right? Before combat ends one of the other players buff the monster +5 to a total power of 14. Now I not stonger anymore. Can I now start asking for help?
Are there any rule that specify how exactly combat resolves? Like when it is possible to ask for help etc.

2) How can I react to curses. Imagine a curse that forces you to discard your whole hand. If you get hit by it you can obviously counter it by playing a card that specifically works against curses. Like a ring of wish (probably). That means you are allowed to counter the curse with an anti-curse card at "instant speed". Are you allowed to play other cards with "instant speed", too - before the curse resolves and you have to discard your hand? Like a lvl up card or a single use card to maybe buff a monster.

Thanks in advance!

greetings