should i put my son in a different pre-school?

[Des]

I called all the schools in our area,asked tones of guestions,and really checked them out.Finally we chose one,my son(3) was very excited to go to school,after taking the tore he actually cryed because he didnt want to leave!He'd been wanting to go to school because when he'd see an airplane or tractor and said he wanted to drive it,I'd told him that he needs to go to school so he can spell his name and get a special paper so he could.Well,the first month went ghreat,it was all he talked about,but know he dose not wanna go,he hides his shoes and will not let go of me and crys when i try to drop him off.It seems like a good school,but the last two times I picked him up have me really worried.One time he was sitting by some other boys playing alone,andf while we were walking out all the other kids were linning up,a little boy behind a girl started pushing her and hitting her,she fot back,it was pretty obvious but none of the staff did anything,the second time i picked my son up,apparently all the kids had just usued the bathroom and my son told the teacher he needed to go again,she wouldnt let him,he ended up dropping his pants and peeing in the playground,and once i got there to pick him up as the teacher was inocently telling me about ten feet away I could here three to four kids fitting in one of those little play houses,again the teachers ignored it,and it was pretty loud.Also,my sons has always been very happy to be around other kids,he's the type when at the park to walk up to any kid and wanna play with them,he's very social so I cant help but to find it strange that he's not really talking there or interacting that much,its not him,plus im worried about what ever it was that made him not wanna go to school when he was so excited to before,plus lately he's become more aggressive and wont take a nap and hardly ssleeps at night.Also,five of the teachers look like they just got out of high school.After this,would it be wise to look for another school,and how do you recomend i make sure its good?