If you see major signs of deferred maintenance, it usually means there is more you cannot see.

Some feedback:Your estimated life appears to be for a new property and you may want to adjust for the actual remaining life of the existing items.If you have not included the following items in repairs and maintenance, you may want to include them here: appliances, cabinets, counter tops, lighting, tubs/shower, windows, doors, gutters and porches/decks.Interior paint - 6 years seems long...$2500 seems high...not sure on sizeFlooring seems high - not sure on size...regional flooring companies in my market are very affordable and reliablePlumbing and electrical - I don't have plans to re-plumb or re-wire units every 20-30 years but do include estimated cap ex for fixtures.Off topic but consider LVT rather than laminate wood...it's very durable and can get wet.  

There's property tax, insurance, trash, water, sewer, property maintenance, state transfer tax on both the buy and sell.

Let’s break it down: you say “Character”, I say “High Maintenance”!

For management, 10% of monthly rent: 90x12x10 = $10,800Maintenance: I think the maintenance for the older units is not represented in the #s above.

I'd say there are a few errors in your assumptions.1) Don't ASSUME 50% for taxes, insurance, HOA, maintenance and vacancy. 

I owned this prop since ’99, I am nearing retirement and don’t care for the hassles of property management and maintenance aspects.

8 percent for vacancy(national average) unless you know the actual vacancy rate for your area (which you should definitely learn), 10 percent for maintenance and 10 percent for capital expenditures.

I can't expect the cash flow of $300+ per door I was getting (doing maintenance myself). 

You can make more cash flow, but there will be less appreciation. more maintenance, and more time involved to manage.