As I've mentioned, I just got the IFF, and gotten Legion on board, and reactivated him. I was hoping to complete the side missions before going into the Omega 4 Relay, but thank goodness I decided to stop by the page for the IFF mission, and learned that time is now of the essence. All the loyalty missions save for Legion are completed, and I have everyone's loyalty, save for Zaeed, and I'm currently romancing Garrus. The only upgrades I still don't have is the Helios Thruster tech, assault rifle accuracy, biotic cooldown, and most of the prototype upgrades.
That's my current state, but should I head immediately to the Omega 4 relay? Or would you recommend doing anything else before I head into the eye of the storm? There's still a lot of uncompleted side missions, and I haven't yet visited Liara's identified resource rich planets. And Legion's loyalty quest has yet to happen. At bare minimum, my goal is to survive the Suicide Mission, along with at least Garrus and Tali since I learned ahead of time that they return for 3, and I don't want any slots that won't be filled up in ME3.