making friends - LONG

Hi -
This may be an old topic for some but I wanted to get some help from those with more experience. My son, age 7, has various special needs. He has learning differences, severe attention problems, some memory issues, severe fine motor delays, some speech issues, and a medical condition (under control). We took him out of parochial school and are homeschooling. This has been very good in most ways: He is learning at his pace, he seems more confident, he is excited to plan and direct some of his learning by picking topics and books, he is doing lots of hands on projects like science, etc. He is much happier and so is our entire family. When he was at school he was not fitting in socially and the aide there to help him did not see it as her role to help him with membership in the class (unbelievable!!!). So...now that he is home we can plan 1:1 time with certain kids he likes and who seem to fit with his style of play (active, imagination oriented). We also spend time with friends and their children that he is very close to. He has a 5 yo brother who has no special needs and happens to be very, very bright and athletic (for the most part they play pretty well together - his brother is very attuned to his play style and while my 7 yo won't sit and play trains with him they do endless pretend play/physical play). We also are trying out a very low key t-ball program and belong to our local YMCA where we swim a lot. This is all to say that he is getting lots of time with kids, both at home and some group kinds of stuff. Here (finally!) is the question: He has been having a really hard time lately (sometimes) saying things like "I quit, I am never playing/talking/ with you again." He runs inside if someone does something he doesn't like or if he isnt' getting his way (i.e. not getting chased the whole time in tag, or getting found first when playing hide and seek). I realize that some of this is normal but I wanted to run it by you all. How much do you intervene/facilitate/hover when your children are playing, especially if you know they need some help. In a way even though these things are hard they are an improvement over the way he played at school - he wandered around or asked to play and was denied or played something in his head. At least now part of the time he is more interactive and it seems more like playing, not observing or seeming unaware. Is there a ? in there. I don't know. All I know is that he is doing much better in lots of ways and even socially to some degree, but the quitting and anger and getting mad at us if we try to help is frustrating. Also, a minor issue: he does drool some and we try to have quiet signals for this and have discussed the social implciations - kids do notice and say stuff. Any ideas. He is very verbal and bright. The drooling is from low tone as a result of getting very sick (comatose) as a baby and caused some residual problems, including the tone issues. He talks a lot about his feelings and says can articulate how it feels to have the anger building him up. I am thinking that while this stuff is hard it is still better than the uninvolved way he was before. Still, it is hard and he takes a lot out on us (of course!). Any thoughts or words of wisdom about making friends/helping or pulling back during the playtime/helping him with these issues? Thanks for listening and for any and all responses!!!