1 - As above, if you can send two ships out every 24 hours, i.e. purely resource voyages in shield (as trade goods ones would take 15 hours min..14:55?), get rudder, then crew, then parts. I'd get the deck parts first.
2 - Generally, replace all your 10k captains with 35k captains as soon as possible. Stats even with a couple of irrelevant traits are far superior to 10k captains. On the General Discussion thread, you could find some more useful information - in particular to maximising effectiveness of the 4x exiles set up in combination with the focus on bones and their stats requirements - according to xpx, the ideal captain set up should be 2 morale, 1 combat, 2 seafaring captains (one of which with 4x multi-talented i.e. 4*50 mcs + 4*100 speed).
3 - When I was in loop/shield, I had 4 statue from ages ago, so I merely rebuild two trees and that was more than enough. So in your case I think you are fine.
4 - Replace all pincer crews first, then work your way through the loop mcs crew; at the same time, get rid of wisp and add another TC merchant. Replace JOD with Exiles when you unlock them. Again, if you intend to go down the bones route later on, the consensus on the General Discussion thread is that you replace a SF crew with another Exile.
Shield should feel a bit hard to begin with, but once the crew gets to lvl 6 or so, it should gradually feel easier. I would not recommend doing trade goods voyages early on, as it tends to upset the 11.35~ schedule and voyages get out of sync. It's much easier to log in and take care of it all in one go.
ps: It took me 9 tries to get Exile done, at which point I was already well over 3700. So there's no need to be discouraged if you can't get it in the first few tries.