Supply movement costs are pretty liberal in this game. 20 for jungle hex, 10 for clear, and 5 for secondary road. That means, that ALL your bases in picture can supply ALL your LCUs. So, you do not need to resupply those bases, just turn stockpiling on, so they do not try to resupply nearby units.
You do not need to drop supply at bases, just put any LCU on coast, and unload supply onto it, it will distribute any extra to nearby units.
You can also wait until day turn, for your transports to arrive at base. Raiders show only at night.
Yup, seems to be best option. Also, depending how strong you are in the area. From most dangerous options:
1) Send your ships there, and bombard. Ships in port are also targeted. Mines, and forts can be a problem.
2) Send your planes there, and bombard port (disbanded ships are also targeted)
3) Keep some of your Combat TFs at ports, or set them to arrive in the same turn, as transports
4) Safest option - put lots of submarines on possible arrival routes, AND put lots of Midget Submarines in port (it seems this is the only use for them). Seriously, you can put there like 20 SSX. They actually attack pretty frequently, just rarely hit something, but you only need one good hit into engines, or some flood damage, which will slow down whole enemy TF.
And, since you can detect enemy TF at night (your submarines will detect it), put some planes on Night Naval Attack. This works only on short distance (IIRC 5 hexes?), so you have to chose nearby base