I am not a professional painter, I just do my own work but times are changing guys... The quality and cost of paints has gone up big time in the last ten years and, you guessed it... some of the processes have changed.
I had a real big problem with spraying paint while it's raining out... but the two part paints don't care. They cure with a chemical reaction and couldn't care less what the humidity is. It's better to spray when it's raining because the dust and bugs are down... I sprayed my truck with Nason BC/CC this spring while it was raining cats a dogs outside and it came out beautifully! Absolutely ZERO blushing (remember spraying laquer when the humidity was a little high?) and it laid down so smooth it was amazing...
Strip the car... metal etch and/or spray a self etching primer like Duponts Vari-Prime and then spray on a high fill epoxy primer/surfacer as your base for body work. It works, my truck is proof and it really helps keep the moisture from leaching back into or under all of your unprimed body work.
Talk to your paint store guys... They are in the business to help and guide you and have an open mind 'cause some of the "new fangled" ideas work pretty well.
And have some fun too!