Small problems with audition

Hello world
I have some problem when with Adobe Audition:
1) because while I have a current recording in Audition when I click, Type to lower even a simple window, Recording stops as if the tow Io??
2) I usually do live recording with an RCA cable from the mixer nel'ingresso tape out of my pc to the mic....The result is good but there is a very annoying background noise is quite evident and do not know how to remove and what depends. I know help??
3) before formatting the PC when it registered that I was registrndo audition the track was played in real time (with a small time delay due to the sound card "series"), Reinstalling after formatting and now I can not get to play the recorded track in real time, But I interromepere registration is play it again, How can I do to feel in real time what the Register????
Thanks to all