Is there any way to delete the Personal (Web) notebook and create new notebooks from OneNote for iOS?
Yeah I have had the same issue and for the same reason.

I think the OneNote app is pretty limited in that area and you are dependent on the web interface alot.

I am not sure if you also use Windows desktop app - but they seem to sync together. 

There is an app called MobileNoter that also syncs with OneNote, only the PC version though. 

In Short there are and you will need to think of some work arounds unless you are able to live with the limitations of the app.

Guess MS really wants you to buy the software on the PC:-)