USB OnThe Go query

i am looking forward to buy experia u
but actually it has no sd card slot

here are my some doubts
1.can i install apps in pendrive or micro sd card(using Apps2SD) using usb OTG
2.do battery last less if i use OTG frequently
3. can i connect a usb mouse and use as a pointer
4. if i connect a high power device will it damage my phone
5 need list of android phones under 16000 which supports USB OTG
6 can OTG replace complete functionality of a micro sd card