It honestly happens more often than you think - but careful!

Electric, gas, trash, and lawn care was provided by the current owner totaling roughly $900 a month for 2018. 

. :)  there is a ton of fraud in that industry so do be careful.

This talks about sending letters to seniors, but the general concept is the same. https://www.biggerpockets.com/member-blogs/11806/84376-your-letter-to-seniors-offer-them-something-they-care-aboutAs for the phone call - I am a believer in answering the phone whenever possible.

They're pretty handy to take care of a variety of tasks.

I told him I'll take care of the place like I own it and he won't hear from me unless it's something major. 

Many times tenants have been subjected to less than ideal conditions from their landlord and are excited about the possibility of having a landlord who cares about them.

Where do I need to be careful and what should be clarified in the deal/contract?. 

Be careful of Stockton. 

Hey Eric,If you've bought the property and already have a trusted tenant-in-waiting, plus a year-long lease agreement prepared, that's the B and one of the big Rs taken care of.