Is the typical mobile device powerful enough to handle the workload of a typical delegate?
Currently the wallet needs around 600MB RAM to run, so no.
Large portion of mobile phones have 1GB+ ram today. It should be possible for the time being to run it. If you make it work and you have sufficient bandwidth.
How much bandwidth do you reckon is sufficient?
I'll provide stats I've collected from one of my seed nodes:
Currently there are peaks of 200 KBps.
It is about 30 KBps on average.
Perhaps the delegate requirement would be even lower as you have less network connections.
EDIT: My stats are the total communication of the network adapters.