1) will they delete it while I'm adding my keywords to the group? Like when I first submit them during group creation. 2) will they delete it if I have some in a diff group?
1) If you add the same keywords (with same matching option) to the AdGroup more than once AdWords will automatically remove the multiple entries. 2) If the same keywords are in multiple AdGroups your ads for these keywords will be rotated so they would choose which ad appears in the ad spot.
I disagree with 2) - I think what happens is the highest scoring keyword will show all the time - the two ad groups will compete with each other, just like you and another AdWords customer compete with the same keyword.
https://adwords.google.com/support/bin/answer.py?answer=40909&query=duplicate+keywords&topic=&type=f This is what happens