Thanks for the replies...
So, they say that they "follow the cues of the baby" as far as naps go. We've tried telling them to keep him up for 3.5 hrs, but they can't seem to keep an eye on the clock. A major problem is that it is one room that he is in and all the babies eat, sleep, and play in one room. So, if another baby is up playing, they are literally 5 feet from where he is trying to sleep. They say that they put him down when we ask, but that he often doesn't fall asleep until an hour later. His naps there are almost always 25-30min. In my opinion, he is exhausted and then wakes up and cries, so they get him up and let him play so he won't wake up anyone else. I wrote a letter to the woman in charge and received back a letter that essentially stated that "they are at a 4:1 ratio" and they were "doing all they could to meet my demands". It is doubtful that they are going to be the solution in this problem.
When he wakes at 4:30, we leave him in his crib. I check his diaper to make sure it isn't wet and cold. I change it if needed and back to bed he goes. If I have just fed him (like at 3 or so)I leave him until he begins to scream, (sometimes he will fall back asleep). If he hasn't eaten all night, I will feed him and hope he falls back asleep. If not, then I take him downstairs so he doesn't wake up his sister.
Our weekends usually start with a bad Friday night, not quite sure why, but maybe because the week is so long? He wakes early on Saturday (see above) he usually sleeps around 8:45-9:30 and goes down again 12:30-1:00 ish. Half the days, he will take a good 1.5 or 2 hr nap. Otherwise, he is up 30 minutes after and I try to let him resettle. If he isn't resettling, I rock him back to sleep. We feed at the same time as during the week. Bedtime is also the same. For the first 2 months of daycare, he consistently did a 1.5-2hr nap AM and PM both days. We watch for tired cues but are starting to see a shift to 30 minute naps in the past 2 weeks. I think his body is just getting used to not ever getting good naps :/