If he's waking up happy from his naps, then you can rest assure he's getting the rest he needs.
I think he's right where he needs to be. If you want to try to extend wake time by 5 or 10 mins, you can try that. But it sounds like he's getting the rest he needs. If he's sleeping 11 hours at night, then he only needs to make up 3-4 during the day.
As for morning wake up time, you may have to live with that for awhile. Most babies are "hard-wired" to wake up at a certain time of the am, and you can try to extend this time by 15-min incraments over the course of a few weeks, but you may or may not be able to do this. Mine was waking at 5:30; we just made it a point never to go to her until 6 unless she was crying out, which she never did. Eventually we got her up to 6:30, but that's about as far as we could get her to sleep. Sometimes she'll sleep as late as 7, but we normally get her up at 6:30 to set her biorhythm for the day.
*HUGS*
Sonya =P