Loaded questions, First thing is to ask your player. 2nd thing is to make sure the coaching and environment suits him.
Does he want to commit to a 10-month program, training 3-4x a week, games on the weekend, fall, winter, spring? Takes a lot of time commitment, dedication on his part and resources on your part to support players in the DA program.
Never too late, but the longer you wait the more difficult it can become to get on a DA team. 03's have already been playing for one season in DA going on two for this upcoming 17-18' season. With a established pool of players already and with some teams not getting promoted the competition for new players I would image will be fierce.
What I normally tell folks is DA can be a good fit if your player is projected to start or maybe be the first off the bench, otherwise unless they love just training playing time can be hard to come by. Just image if your player spent all week or weeks training, then basically all day for one game out of town (2 hrs each way travel (SD to LA for example), 1.5 game, 1hr warm up) and he plays only 5-10 mins or not at all.
College recruiting can be good for DA starting players if they graduate with the program, play for the well known established or playoff teams, or are just plain great players but they same could be said for most highly competitive club teams that play the major tournaments for example.