I just finished Cage of Fire and have no more Missions near my level (only far below). Is that it? Do I now grind until I can get to RA5 to find the interesting content?
If it is, any suggestions on how best/quickest to get to RA5?
Farm "Explore" missions for the badges for your consoles and torpedo weapons, until you hit RA-3. Once you're RA-3, you can take the transwarp gate to Battle Group Omega, where there is enough content to get you to RA-5 without a problem.