If you really want to do it, then
1. Put on the lease that each pays 1/3 of the utilities.
2. Each of them should have cell phone, so you don't need to put the landline.
I would rather include all other utilities, cable, internet, and washer & drier in the base rent while charge a higher rent.
Yes, you can charge someone for the garage.
One person each room should be the maximum you want in this house. Do not put anyone in the living/family room as this will make the other people uncomfort.