Supergulo:
I love that you liked it. "caveman in rubbersuit" came from that there was a ZC quest where the Samus tiles looked like "caveman in rubber suit" and I even told it in the comments.
So, you don't need to go to Frozen Waste yet. Go to the southwest of the caves, there were obstacles, but now there aren't.

dennputt:
When you see the blowing octorok, go north JUST til there are vines, don't go through them. So, go just 3 screens north. Then one left and boomerang the stone. Go north, stab/slash the flashing block, go into warp then go just north and north til you can (don't worry anything, just go north and north and north...) then when you can't go norther, go east, open shortcut. From there, go west 2 times, burn minitree to the south, go south and then all the way west.
Russ:
Remember that you can burn the big block at the north, in the 4-way intersection. You can bomb the shutter in the southeast corner of F1. You can burn some funny looking 16x16 blocks.
Elmensajero:
Yes, Fire Shield is in LW, too. Probably most well hidden secret, I don't know how did some figure out. There aren't even the secret sounds enabled on that screen.
Nashvillan:
Oh, you cheeky impatient fellow:

Those spikes disappear after you beat the second dungeon.
That key? Flip one of the switches. So, keep walking just before those switches and remember that usually only the lower half works of the trigger combos.