I do have some questions about it but I'll cover those elsewhere; I don't want to clutter up this post with that.Am I correct in understanding that if I decide that a house needs, say, paint inside & out, carpets, a new dishwasher and over-the-range microwave, a runny faucet fixed, and moderate landscaping work, I can't do any of that myself, and also can't hire contractors to do it, but must  hire a General Contractor to manage all the work?

Consider paying for a professional cleaner to really make the property shine.

When we found this deal, there was apparant damage to the carpets in the basement from pet waste, which I immediately thought was an excellent opportunity to get into this house as I was willing to spend some time and money rehabing, where most homebuyers wouldn't be.

The one couple even steam cleaned the carpets.

@James Galla hopefully I understand this right so are you saying if you set aside 20k for a rental property that you bought and say you need to replace the carpet and it cost 2k you would take this expense out of your income from the property in a gradual manner to replace those funds but not explicitly continue to take out money once those funds have been replaced because over time this would become disporportional. 

the key is finding a good cleaner which is the your #1 contractor critical to your business.If you have a local SF bay area Airbnb, there is a bay area startup called "getproperly" that is a cleaning calendar app plus a convenient way to find cleaners in the area that are specific to STR (Short term rentals).Once you get beyond a certain number and/or you get a lot of bookings, you may want to hire a "cohost" first. 

My husband is an electrician now and use to lay carpet when we first met.

Repaint (make it a shade of grey), get rid of any carpeting, put down luxury vinyl laminate flooring. 

replaced the heating system to include central air. replace the carpeting with hard wood floors What was the outcome?

The carpet was brand new two years ago and it's been kept well.