In the first one you just won't know some things, like to purchase cabinets way in advance, or how to schedule your subs, or to know when you're being taken for a ride.  

If, though, when you say "updating" you mean that you are gutting the interior of the unit, putting in new cabinets, new counter-tops etc, then I agree that you have a renovation/improvement project and the windows would be capitalized as a part of that project.

Tenant calls and says there's problem with water dripping down from the faucet in to the cabinet.

Or to get prime rental rates I should do a nice rehab with sterlnig silver appliances, and good cabinets?

I have several houses now and my filing cabinets are getting a little stuffed.

Spray before installing flooring, cabinets, etc. 2.

If it's that easy, you should have done it long ago, throwing in some cabinets and a work level surface.  

When you consider your reserves for the replacement of floors, cabinets, fixtures, roofs, DHW, HVAC, etc., you will find most residential properties (1 - 4 units) will fall into the that 40 - 60% window over the long-term.

Often properties that need a cosmetic rehab (patch walls that were kicked in, cabinets that were trashed, etc.) turn inexperienced investors off and they can't look past the condition and see the potential. 

I just bought a 600 square foot property and I got a quote for $8500 to completely gut the interior and basement (Plaster walls/ceilings, cabinets, bathroom, trim, some carpet, and a few rotten walls, bathroom, and drywall in basement).