CapEx {5000$ per 7 years for paint and replacing cabinets}7.

It includes an allowance for appliances and all finishes which include bamboo and tile flooring, solid wood kitchen cabinets, black or basic stainless appliances, WiFi thermostats, closed circuit camera security, granite counters in kitchens.  

I have a friend who's tenants showered without curtains for a couple years and completely destroyed the bathroom cabinet.

These units are cheap tile, cheap $200 cabinets from Home Depot, and pretty low cost appliances.  

I need to remodel a rental--new cabinets, countertops, appliances, flooring, bathroom updates, some minor electrical and plumbing, etc.

Cabinets?

I plan on quitting my job when I purchase my first investment property and doing the rehab myself ( as a GC and labor work, I can build kitchen cabinets, tile work, flooring... ).What financing strategy should I use to start with considering I'm willing to put 20% down and paying for the rehab?

I would shrink your cabinets a little.

Lastly, if you really want to do renovations, check out the local trade school and go take some classes on electrical, or plumbing, dry wall, learn how to hang cabinets.. all this stuff you will be paying for -- why not learn to do it yourself?   

It is not only the floors that are uneven, everything in the house is out of plumb, none of the corners are 90 degrees anymore, which makes everything from installing windnows or doors to hanging cabinets so much more difficlut, nothing fits, everything needs to be custom fit and shimmied up.A better solution would be to see where the foundation is sagging and try to adress that.