Thanks for the feedback and question: I worried/wondered the same.
How it's going: one sale as of now (deal is one day old).
To be honest if I ever get in trouble for selling too much on AppSumo this will be a good problem for me. Right now I am looking at getting as much user feedback as possible so no I am not worried.
As of now the product feature set is not so big so support wise I should be fine.
30 days to 14 days that's a good point. I went for the de-facto standard without thinking it too much, if you have more details I'd be happy to learn. I might just try 14 days and see how it goes too.