bed time routines..it's driving me crazy!

I have been cutting down his nappings to 30 minutes a day.  Imagine from the time (a year ago) he used to nap for 3 hours? The only reason I'm cutting down his naps is because he doesn't go to sleep until late.  But it seems not really the "CASE"..I don't think.   I figured it will take few weeks to get to used to that.  Now it's two and half weeks later.  His bed time is still struggling..varies from one night to another.   ugh.   When I wake him up from nap.boy is he ever cranky!! I just leave him alone and do my own thing.  Don't let him get to me! You know I get irriated easily. WHEN he doesn't have a nap..WATCH out..its not fun to watch him get into tempers several time from afternoon to bed time.  I don't want to deal with that.   He is uncooperative, would scream, cry and cry and so on.    So anyway, when it's bed time..it is somewhat better but not every night.  Some nights, he just fall asleep within 10 minutes, but other night..a hour and half later WITH our intervention!! We had to come in few times to "settled" him down.  (we have a video monitor..old one , used to be for CA when she was a baby)  We did tried several different things to see whether he can fall asleep on his own  when he is playing, signing to himself, waving arms..it would take him a hour or so to go sleep!   Then of course, he never sleep in, he gets up at same time every morning!  Regardless of when he goes to bed (not eariler..but I'm tempting..)
We had to get into his room to stop his "playing"..moving so much and signing.  We thought it (playing/talking) would help him to fall asleep faster but it doesn't ..it makes him wide awake even more!  therefore, bed time stretch to later time! I kid you not.   So we have to sit with him when he is like that , to remind him to not to "play" by firmly touch him by his back.   Sometimes it takes few attempts then eventually he fall asleep.  Sean said he doesn't want to do this anymore!  Neither do I!   I am not sure what to do..
Someone said just leave him..and he is not going anywhere, eventually he will go asleep.  I had to laugh..that is not easy.  Because he will be very cranky the next day, I have to "deal with him"..we would not enjoy our outing or plans if he is that mood.  And what about school?  Then he will be uncooperative, misbehaving and tired in classroom.  He will miss the learning stuff. 
Any thoughts...I am up to this point to ask the doctor about this. 

We