Converting a Single Family into a Multi-family

[Steve Salvini]

I'm currently looking a 3,000sf single family home that was once a multi-unit and zoned R2 (2 unit) but also had an apartment in the attic, which I would need a variance to convert back to a third unit.  The first floor is move in ready and the second floor and top floor still have the kitchens, as well as plumbing for the bathrooms (second floor bath is complete).  It's more then I would like to spend but my thought is to purchase as a conventional single family, live on the second floor, rent the bottom unit immediately, and work on figuring out the top floor and rehabbing it.  This is a hard area to find multi-units and especially three units as they are sold immediately. 

Questions:

How hard and what is the cost to have separate heating, electrical, and water on each floor for utility purpose?  Would/should I do this?

Since its a single family now and zoned R2, can I just convert back to a 2 unit with no issues from the municipality?

Will converting it back to multi after I purchase as a single family going to affect the loan?

Would all the units require two entries?

Thanks!