Right now it's probably best to go to AppMobi for support, we haven't tried it ourselves so they're the best people to help you there.
I think there tends to be a small developer fee for two reasons:
1) keep out 'script kiddies' who just want to mess around - they won't bother if it costs them money, and
2) keep out viruses and malware, since if anyone submits any, they've got the author's payment details which is a great place to track someone down!
TBH if you're serious about app development $99 isn't a big hurdle, it's more there to keep the wrong people out IMO.
Not really, The reason why corporates want money to the developers that could reduce the saturation of apps are waiting to be approved, so it happened like Steam Greenlight.
There a lot of apps are fraud, jokes, chinese copy cat, etc. are on app store from Apple.
Besides script kiddies, virus and malware apps can easily be rejected by corporate staffs and ban their IP who published apps, no need to ask the fee. The reason is the script kiddies are enough stupid to pay fee and publish malware apps, then get banned and lose account.