Yeah, I really wish they spaced things out more. I mean, you hit LtCmdr at level 10! If they had all the ranks from canon (including the on-again, off-again Commodore) we'd just be hitting Rear Admiral, Upper Half (if you leave the promotion points where they currently are, and just rename things):

Level | Current rank             | Proposed rank
------|--------------------------|--------------------------
 1    | Cadet/Ensign             | Cadet
 3    | Lieutenant               | Ensign
10    | Lieutenant Commander     | Lieutenant J.G.
20    | Commander                | Lieutenant
30    | Captain                  | Lieutenant Commander
40    | Rear Admiral, Lower Half | Commander
45    | Rear Admiral, Upper Half | Captain
50    | Vice Admiral             | Commodore
55    | Admiral                  | Rear Admiral, Lower Half
60    | Fleet Admiral            | Rear Admiral, Upper Half
65    | N/A                      | Vice Admiral
70    | N/A                      | Admiral
75    | N/A                      | Fleet Admiral