I should have the benefit of getting accurate expense and income data for any real property to validate cap rate and other information.Property management costs are similar to what they are for a SFH (10%/mo + placement fee) until you get to a certain number of units where it then makes sense to hire an employee.Insurance costs will be proportionally more than a SFH/4plex in the area would. e.g.

I’ve been tracking it about quarterly for years even before RI and always update year end when preparing for taxes since I’m collecting much of the data anyway.

Also, if either of us wanted to transfer full ownership to one of us later on, will that result in a taxable transaction?

You can also access public records such as deeds and assessor data. 

Net profit after commissions and transfer tax will be $55,693, or 82% ROI.

The only out of pocket expense is to pay of the title transfer.  

One thing that I messed up on was not stating in the contract that all security deposits were to be transferred through escrow and that turned into a whole ordeal. 14 days inspection contingency is necessary, and if possible I would definitely ask for the tenants inspection so you can find our if they are happy with the property manager and or rental itself.Title Company:I went through and asked for references for title companies again from lenders and friends.

You subscribe to them and they will provide you with the same data that realtor or appraiser would see (also very different than what is on zillow since you just see the "sold" price).  

The Median house price, for the recent NEFAR data Nov 2018 is $225,000. 30 year rates are about %0.75 higher than this time last year. 

You can find cheap data entry experts on Upwork or Fiverr who can do the work for you in a short time.