Hi P.. My kids were very close in age too, so I completely sympathize with how hectic things are for you. Sleep deprivation is the worst (but you are only a few months away, so hang in there!!)
It's so difficult to tell what's going on with a child entering his twos! It could be so many things!! Your son is becoming so much more independent and will be testing you like crazy -- over everything (feeding, bathing, sleeping, everything!!) I don't think you are missing anything!
My suggestion is this: stay the course with his sleep schedule and, as tough as it might be, stop responding to him when he is trying to get your attention during sleep time. My daughter still sometimes "tricks" us too -- she will scream in the middle of the night as if she is terribly ill (which is terrifying) and when I enter her room she asks me to fix her blanket or give her a hug. That's when I know that I have to stop going in her room for a few nights!
I have found that (unless something is medically or otherwise wrong with the child) these little blips in behavior tend to last up to 2 weeks and then go away. So if you hold your course, you should see him resume to "normal."
Personally, I would NOT decrease the amount of sleep he is getting at night! Sleep begets sleep, and he will be healthier getting the amount of sleep his body is demanding. According to "Toddler 411" book (by Denise Fields and Ari Brown, MD), a child 1-3 years old requires 13 hours of sleep per 24 hours period (including naps). But if your son is getting an hour more, that is absolutely great for him! When he starts staying awake in bed longer and longer after you put him to bed, on a consistent basis, that's when you'll want to start adjusting his bedtime.
Hang in there Mama! It's tough times now, but it will get easier (especially when you start getting more sleep!!)