The home inspector was rude to me the buyer's agent and even accused me to work for the seller, as I was continuously asking him questions on how much that issue that he was making a big deal will cost to be fixed ( $15), how long it will take for the house to fell down because there is a bit of rust on the railing of the balcony of a 5-year-old home ( answer 60+ years if the railing is not cleaned and repainted  which was $100 worth repair).You get the message. 

Put new PEX supply lines in, repainted everything, rebuilt some windows and repaired others.

It isn't exciting but it is very neutral, and cuts in easy for repaints.

I’m not sure if this was done on purpose or because they had been repainted and dried shut over the years.

I plan to move forward repainting the entire interior.

Are repainted cabinets fine with tenants, or do you need new, modern flat panel cabinets to get your underwritten rents?

You are correct that you will likely have to repaint them occasionally if you choose to paint them white now, but the place will look fresher in my opinion if you do.

The builder used fans to dry the walls, repainted the walls and have test results showing there is 0 moisture now.

Repaint as needed yes.

If the tenants do, charge them to repair the damage and repaint the wall.