I, too am putting a 1750 list together - see my list here:
http://www.dakkadakka.com/dakkaforum/posts/list/446922.page
It is a bit different to yours for the reasons that I outlined in the thread, plus I just don't want to put my troops in transports, foolish or not - it's just not the way I want to play.
I have played a few games proxying my
GK models as Corsairs now and a couple of things I have found are:
The prince is great. Nightfighting is awesome, as is his S9 AP2 large blast void strike with his
BS 6. Trying to fit in another prince is something I am considering.
Shadow spectres are pretty good - their weaponry is nice and the fact that they get a 4+ invul against attacks over 12" means that they can stand forward of your more fragile troops, drawing fire from them allowing them to advance. My only problem is that a 6 man squad with exarch, the exarch powers and exarch weapon upgrade, they are around 247 points. You can take quite a lot for that and I'm not too sure they are an optimal choice when you can take more hornets, wasps, warp hunters, maybe another prince etc etc.
As you said, getting those corsairs troops on foot to objectives is difficult if you don't have much cover. I have found that they do die quite quickly, although taking a felarch means you don't fail too many
LD tests.
My list is capable of an awesome alpha strike from long range but I have found that due to the fragility of some of the options, your offensive options can drop off quite sharply.
I really like the corsairs so far. They are interesting to play and can be very powerful - they just take a bit of finesse to see a game out, especially if it goes to 7 turns but the challenge is enjoyable.