I prefer to have all the income and expenses tracked to the penny and my accountant appreciates it as well come tax time (lower tax prep bill). 

Either way they had to run credit checks on all 4 and cosigners and keep track of 4 rents, so nothing was different. and there was nothing that could stop them from doing that, so i told them i would agree to $300/ lease for a group and $100 / person if separate leases, so they make $100 more on a group of 4, not $900. but they do a lot of other things that free up my time and i do not have to worry about, listing, background checks, leases, maintenance issues, collecting rents, etc. they are worth it for me since my properties are 3 hours away.

Track everything you do and review them regularly.  

Would be great to track each other's progress.Nick

You need to do some deals on your own to show a track record before a lender will trust you.

You trained him and need to get your focus back on track .

Yes, you should be tracking mileage and expenses.  

If you run it all as one business, keep track of all of the finances together and report on them all together on your taxes then 1 account would make the most sense. 

I am a process guy so I like to set things up, give them some time, tweak them and track the results.

My view is there are some good investments and some marginal ones but they seemingly have a decent track record of paying off.