Some thoughts on Naval Missions:
I got all the rings before they made it a lot easier (with like 700-800 missions completed). My suggestion is not to worry about losing ships too much. This is a battle of attrition. Since the nerfs, a 90% success rate guarantees that your ship won't be lost. I've tried to kill off ships with crappy crews by send them in with 70-89%, and even then, they never seem to die. The only missions that I ever fully optimized were the ring missions themselves.
If you've got time, do the Tannan faction dailies to unlock the Oil Rig mission, Unsinkable equipment, and the Awakener ship. Protect your ships with Murloc crews; they are rare (maybe put Unsinkable on them). Optimize your garrison for producing garrison resources by getting the Inn and recruiting followers with the Scavenger trait (or reroll current followers).
Do all the missions in the NE corner (on Alliance at least, I never did horde), and any treasure missions that pop up. Doing bonus missions when the come up will help you get an achievement, and should a ring mission happen to pop up while the bonus is active, you'll have that going for you.
I really like the gnome/troll ships. They really do bring back a ton of equipment over time. My bags are full of the equipment items from them. Nelf/belf crews help to speed things up. And a have few key ships with human/undead and/or panda to max out the ring missions.
Now that I'm done with all that. I've just turned the naval missions into another source of income. Got dwarf crews to bring back more gold, and nelves to bring back money faster. I pay my sub with a different character every month. Haven't paid Blizzard in months, even after buying a ton of crap.
No reason you can't get your rings in the months before Legion.