Oh boy. Sounds like you're right in the middle of the 2-1 nap transition. To be honest, I think you're actually going to have a fairly easy time of it, even though it doesn't seem like it right now!
Typically what happens is you limit the AM nap to about 30 minutes so that you can still get a longish nap (1.5 hours) in the PM. However, your son sounds ready to head straight for 1 nap at the middle of the day, if he's able to stay awake until noon! You're having the typical problem of a shortish (1.5 hr) nap at noon, which means waking up at 1:30 and leaves an AWFUL long stretch until bedtime (you're saying 7:30/8, right?). Normally what happens is your child's nap just starts extending into 2-3 hours as their body realizes there won't be a 2nd nap happening. They're so used to having more than 1 nap that it takes a few days to a week for that to resolve.
The other sleep problems you are mentioning are all stemming from being OT because the 1 nap is short and bedtime is about 6 hours later -- WAY too long for this age. So, you've got a couple of options:
1) make that bedtime MUCH earlier -- more like 6 pm. I know that sounds daft, but believe me, your child is super OT at this point and needs the sleep. If you still get a 5:30 am waking, at least you'll have had an 11.5 hr night instead of only 10 hours! BTW, waking after 10 hours of sleep is CLASSIC OT behavior, so I believe that is the source of your EWs.
2) I don't know what your history has been with falling asleep, but what you're describing now (taking up to 50 minutes) is very indicative of OT behavior as well. 15-20 minutes is more typical time for falling asleep if you catch their sleep window.
Has your child ever been able to fall asleep on his own, without you there? If not, we can help you work on that! You're headed in the right direction (putting him in his crib awake), but we need to get you out of the room so that he can fall asleep on his own. Why don't you tell me more about his sleep history and we can see if there's something we can do now, or if this is something that will resolve once the OT is fixed.
3) No more taking to bed! I know it's so hard when they wake so early! but this is a prop that you will really really learn to regret! I'd prefer that you go and lay on his floor, if you are just so tired and he won't stop crying. At 14 months old, though, you may be able to put a clock in his room that is set for 6:30, and say "When the dinger goes off, that means it's time to get up! Until then, you need to play quietly in your crib." The first few days, he probably will still call for you. You will just go in his room, and gently remind him about the dinger and how that means it's morning time! Then, when the dinger goes off you go promptly into his room and act really excited and happy "Yay! It's morning time! Let's get up and get ready for the day! I know we're going to have lots of fun today!" That sort of thing. Again, it may take him a few days to get this right, but knowing that he just needs to way for the alarm to go off will help him to know that playing on his own is temporary, and that you'll happily come get him eventually.
I suggest trying that REALLY early bedtime for at least 3 days and see where that gets you. Another thing you can try is alternating 1 and 2 nap days. IN other words, after a 1 nap day he's going to be more tired so you may be able to get a very short nap in the AM (no more than 30 minutes, and you can go as short as 15-20 if you still have trouble getting a PM nap) and then a longer nap in the PM. I was terrified to wake my son in the AM nap but as usual the BW advisors who told me to do that were right!
If you're going to try for an AM nap, I'd probably shoot for around 10:30 or 11. That means waking at 11/11:30, and then another go at a nap around 3 (ending no later than 4:30). That sets you up for an 8 pm bedtime pretty easily. And actually, after a 1 nap day and a 5:30 am waking, he'll probably be ready for that first nap around 10-10:30. That would be really good.
So, 1) earlier bedtime on 1 nap days, 2) try alternating 1 and 2 nap days, and 3) limit AM nap to no more than 30 minutes. If trying the 2 naps, I'd probably experiment with the earlier nap time of 10 am and see how he does (waking no later than 10:30). I have a feeling he's so OT, that he'd welcome that earlier nap time.
Let me know how it goes! The 2-1 nap transition is one of the harest sleep phases, but also one of the most rewarding when it's over!