lucysmom has given you great advice, I have been following the thread, but felt there was not much I couuld add.
I do strongly agree at least part of it is the dummy that is the problem, the reason I think this is your little fellow reminds me of my ds#1 & he would sleep pretty well the first few hours & then wake heaps the rest of the night & would settle with the dummy (until about 5am, when he wanted a feed)
The reasons - 45min naps, & the constant waking.
The fact he doesn't wake when it falls out says it just falls out when he is in a deep cycle, but when he gets to a light sleep phase he needs it to go back to sleep.
Sorry I have to be the confirmer of bad news, but I do think that is the main cause of the problem, combined with what sounds like a spirited bub, which from my own experience means (unfortunately) every little milestone etc is going to be hard work & his sleeping through the night will probably be pretty erratic over the next 2 years if my experience is anything to go by.
I would gather together some strength & ditch the dummy if it was me... I left it till much later with ds#1 & boy has it been hard...not there yet & he is 31 months