I don't know squat about SQL.
But I love games. And SFB. And SFC. So I'll comment anyway, and forgive me in advance if I say anything stupid or unintentionally off topic.
Regarding means of spending prestige points: I always thought that Prestige should CONSTANTLY be whittling away. That, ultimately, in Space Navy, one's prestige, to a point, depends on a "What have you done for the Empire LATELY?" perspective. What's more, the more you deliver, the more is expected of you. So, if you cash in a tremendous amount of prestige on a battle fleet, well, I'd expect the prestige cost, that is the empire's "expectation" of what you produce, to go up accordingly. And, if, after buying your battle fleet, you can't keep up with the PP "payments", well, the navy repossesses.
So what this does is, it means that you don't "buy" a ship so much as "rent" it from the navy, and the navy expects a regular payback from a steady stream of Prestige Points. Now, if you earn Prestige in "excess" of the rent, well, that gives you free time with your navy to go exploring/cherry pick easy missions, which you can bankroll. Note that this model should give some counter, depending on the setup, of the inevitable escalation of player-controlled fleets within an empire. In other words, it'll be harder for any given player to MAINTAIN a huge fleet unless he's out there using it a lot (and hence potentially getting blown up in the process). Furthermore, it gives an incentive to stick with small bread & butter ships which make up the backbone of all the navies, as it becomes easier in some respect to accumulate PP in a modest fleet than a large one.
Just my thoughts. Hope they're relevant in this thread.
-TF