I can't offer experience but I can offer support. After listening to RipkenFan talk for a game about some of the ups and downs of the minor league players on his son's team, I can see why there is serious parental anxiousness. Minor league parents you have my full support. Minor league rosters are constantly changing, and the evaluation process is probably different than most people understand. RipkenFan gave me a lesson on how players are evaluated, and I learned some new things.
Yes, your son has decided this is how he is going to make a living, but it is a tough living and in full public view. 5000 people weren't watching me do my first real job out of college. A former neighbor of ours made it to the MLB and Korean Professional baseball for a bunch of years. I was talking to him at his parents Christmas party and he was telling how difficult it is for him as well as his parents. I think it takes a special parent to really understand what it is like for a son or daughter to play a sport professionally, anywhere at any level. I look at somebody like Petr Korda and his wife Regina. They have two daughters playing professional golf at the highest levels of the LPGA and a son (Sebastian) who is rising through the ATP ranks quickly as a 21 year old who will soon be a top 10 tennis player in the world. They must buy Tums by the caseload at Costco.
Best of luck to all of our minor league parents!