To do piracy in iOS, you have to jailbreak iOS device. If you compare to Android, you can consider it negligible.

Nah uh.

You can simply resign an IPA as your own. There's a bunch of websites offering their signing certificates a service specifically for pirates.

Why on earth would anyone bother to pirate a $0.99 app???

I've absolutely no idea.

There are lot of advantages of creating native mobile apps like GUI, performance, reliability compared to mobile website or cross platform solutions. You can check some detailed explanation at http://theappentrepreneur.com/app-entrepreneurs-dilemma-to-g....

We have been using http://justinmind.com for prototyping. It's worth trying.