I'm only slightly ahead of you (I've gone on two side quests outside the citadel, and I think I'm up to about 11 hours).
I hung out in the Citadel for quite awhile doing all the sidequests I could, since I figured it'd be an easy way to level up before you leave. I couldn't find the last keeper (I have 20/21) so I left and did a couple side quests that people there had given to me.
I'm not sure it really matters what you do. It seems pretty open to me, since you can always go back to the citadel to continue with the sidequests.
I haven't even done any plot missions other than what you do in the Citadel. Although I had to start taking notes to revisit planets where I found something my skills weren't up to par (like probes where my decryption level wasn't sufficient). I wish there was a way to mark these in the game as "places to revisit"
Anyways, I think you're fine with leaving and going exploring.
I hung out in the Citadel for quite awhile doing all the sidequests I could, since I figured it'd be an easy way to level up before you leave. I couldn't find the last keeper (I have 20/21) so I left and did a couple side quests that people there had given to me.
I'm not sure it really matters what you do. It seems pretty open to me, since you can always go back to the citadel to continue with the sidequests.
I haven't even done any plot missions other than what you do in the Citadel. Although I had to start taking notes to revisit planets where I found something my skills weren't up to par (like probes where my decryption level wasn't sufficient). I wish there was a way to mark these in the game as "places to revisit"
Anyways, I think you're fine with leaving and going exploring.