Sorry for piggy backing on this guys post, but I'm new and cannot post a new thread yet. Relating to his question, when you trade Dilithium for Zen, can you really buy/unlock everything Zen paid for with Money can buy/unlock, such as extra character slots? I do plan on buying a limited amount of Zen, so I want to know what I should save that for, and use the Zen I get from Dil trading for ships and etc.
Yup, any Zen you buy from the store or buy ingame via the Dil exchange is exacually the same, no difference when it comes down to buying upgrades like extra slots, EC upgrade ect
One good thing most people do is get a sub for 1 month while levelling up your characters as when you drop back to silver (F2P) you get to keep the bonuses earned - its best to find a cheap unopened copy of the game for the game code with 1 month of gold membership as it will be cheaper than a sub
With that you get 1 respec token every 10 levels, 500 Zen (normally to buy the EC upgrade with), Account Bank, extra Inventory, Extra Bank slots, more BO slots and i think a couple of other goodies
STOWiki might help you
All the quests/missions can be replayed, if you do a lieutent mission and like the item at maximum level you could go back and redo the mission and get the item again but with better stats ect