Thanks for all the comments. After 4 years of using this coop it is great. The water and feeder are especially useful in reducing the maintenance and allowing us to go on vacation while only needing to find someone to collect eggs.
The open air design is working well and with no problems even...
Low volatility paints are never a bad idea, but compared to the inside of a house this coop has a ton more ventilation, so any sort of odor or chemical is diluted much faster than in a house.