AFter I beat Ridley and gained scew attack, I tried every way possible via tubes or gaining access to inner pathways and I was blocked at every turn. The main ways had locked doors after the recharge stations. I then figured I missed some opporutunity so I just went on to the end. Beat the game and out of curiousity looked up a walkthrough to see where I missed my final opportunity as it seemed odd that many areas required screw attack, but I couldn't get it until after ridley.

The walkthrough stated to not use a recharge station after you beat ridley or its all locked down. Now, I haven't continued post-ending, but I would assume its open now.

Is there even post-ending gameplay in Fusion? I just remember it loads the last saved game if you load the game again.

Nevertheless, congrats on beating Fusion! The next-to-last boss fight is the hardest in the entire series in my opinion, at least until you find out how to exploit the AI. But I was pretty underleveled though.

Yeah when I beat ridley, I got remaining items I saw in that area then went back to main terminal and recharged/saved/nav. Had I known of the lock down, I would have used the inner tubes at that point. Ah well. I'll give it a 2nd go later.

That's weird I don't think I've avoided any recharge station or terminal and I saved on the closest save possible before the final boss (SA-X) and I wasn't locked out of anything when I decided to go back in each sector to get all the items.

That is weird.

I tried every main access and locked after the recharge rooms. I also Tried to go to different areas once I went and saved closest to SA-X. But then gave up and just went on to fight SA-X.

http://metroid.retropixel.net/games/metroid4/walkthrough/15.php#ridley

That is the walkthrough I read afterwards that mentioned the warning. See the red NOTE towards the end. From that I gather my issue was that I returned to the main entrance vs sticking to the hidden pathways.

Ah sweet.