Is there a place to assign Mr Handy to another floor or heal Mr Handy?
To assign a Mr. Handy to another floor just drag it there like you would a dweller. As far as I know, the only way to heal it is to pay 2000 caps once it's destroyed.
I've got one that's down to about 25% percent health thanks to molerat and radroach attacks, so I'll be forking it over pretty soon.