Is it really that hard to find search field and use it for once?

I suggest you at least find sticky and read them, becasue even if I try to answer your question it not going to be sufficient.

1) go to macro section and read on macros, and how to make macros to accept shared quests, but rest you have to switch wow windows and use your mouse for most not shareable quests from main.

2) there no such thing as "auto" in multi-boxing terminology, because it refers to close to botting, big No NO around here, but you can read unswer for next your question and draw a conclusion and maybe answer.

3) there few programs that completely legal, because they don't have any scripting or logic parameters to check, What they do is to copy key <<1>> on both wow windows you have.

keyclone is easy to set up and have best support out off know software out here, but coasts $20
HotKey.net is free, and a bit harder to set up, with less support
Octopus is free too, and same as Hotkey.net regardless support and setup

hope it helped, but really just look over forums first before asking any others questions