Whew girl!
You make me tired just reading all the things you've got going on in the next few days/weeks! They seriously need to make a sleepy smiley face, I would use that one a lot!
I do think you are looking a bit too far in the future with the dropping the 1 nap. He may not do it for another 6mo to a year.
It does sound like today he was OT, because those are the same things my dd would do - esp the waking 45min after being put to bed, and the EW's. And no, I don't think if he wakes at 3pm he'll be able to make it to a 7pm bedtime. My dd STILL doesn't go 4hrs awake.
Until you get shots, and moved, I don't know how well you'll be able to implement anything in the mornings to stretch the A times. Once you get a bit settled where you are going, I would think something like this might work ok for him:
E 7 (you would adjust everything earlier if he wakes earlier)
A 7-9:30 - maybe a little longer depending on cues
S 9:30-11
E 11
A 11-1:30 or 2 depending on tired cues
S 2-4 - this is how you would get your later bedtime - because nap would be later
E 4
A 4-7
E a few minutes before bed - 6:45ish
S 7 for the night
DF btwn 10-11 if you do one, if you don't, ignore this.
That is about what our routine looked like at that age. That would give him 3-3.5hrs of daytime sleep and that is a really great amount. If you find that you are having problems with the afternoon nap once you've let the am nap go a little longer, I still wouldn't wake him from the am nap until he is a little older, I would just allow him a little bit more A time between the am and pm nap. I don't think I started waking dd from her am nap till more like 10mo, although some moms have to do it around 8-9mo, I just still think he is a bit young to limit that am nap to less than 1.5hrs, but every baby is different! So I hope that helps you figure out a plan of attack when life settles down a little bit for you!
I hope that your move goes smoothly, and that your children will adjust to life in a new home and place very quickly!!! Good luck, and let us know how you get along!