DWetzel,
I agree completely on points 1 and 2.
On point 3 I would suggest: just ignore Utrecht for the moment. It produces a spear every 18 turns, so doesn't pose any threat at all. After we take the rest of the Dutch towns, it becomes the capital and then we can take it without auto-razing it. This saves a settler.
And point 4: yes, what Optional says is definitely right! Sending units to Greece by galley takes 1 turn, going on foot will take 40-50 turns! (No way we can build roads down there beyond the choke point!) So if we want to attack at a given point in time, then we have 40 more turns to produce units, so we will be able to make more units bear down on the Greek, if we build a couple galleys, not less! (You seem to be under the impression that if we build a couple of galleys this will substract from the number of horsemen we will have for attacking Greece. Quite the opposite is the case.)
Let me refine that strategy: you were wondering, whether the AI would attack at the choke point or not. Well, we can make them attack there! Just put an empty undefended town on our side of the choke point, then the AI will desperately try to get there... It works like a magnet...

(As a matter of fact, I used this in my turnset for making the Dutch spearman walking back and forth until I had enough archers to take care of him: undefended Frankfurt played the role of the magnet. Then whenever the spear was at Leipzigs borders, I closed the gap and he would walk back south trying to get to some other undefended spot. Then I opened the gap again and next turn he walked back north... By the time my archers were ready, that poor guy was so dizzy from running around in circles, he didn't put up any resistance at all...

)
Anyway, while the AI is marching their units through the jungle for dozens and dozens of turns, we just prepare our landing force and then quickly unload them right in their backyard! Saves a lot of time and we meet much less resistance than fighting our way up north through the jungle.
I'm not completely sure about the following, but I think if we unload our units on a mountain outside their territory, they will even ignore that stack (as long as an undefended town is waiting for them on the other side of the continent...) and we can take our time for building up the stack over several turns. That way we need only 2-3 galleys.