The rooms you suggested were tricky, but look easier than the others. I really liked the solutions as well (or at least what I think the solutions are). I'll delete these comments once the hold is uploaded since they may contain the solutions a bit.
3S 1E
Click here to view the secret text
×At no point in the loop the fireballs were going through was I able to step on the fuse without the oncoming roach disrupting one of their movements. So I think I'll have to analyze each point in the loop and list down the points in the loop where the roach only disturbs 1 of the fireballs. Then I'll halt that fireballs movement with the 2nd roach and see if it helps me beat the room.
5S 1E
Click here to view the secret text
×Similar to the Chaco's version, it looks like I'll have to substitute a fireball for the mimic. If I have one fireball going down the left wall and one going down the right, it looks like I can get the right fireball going up the trapdoors if it moves earlier than the left, so looking at the movement order, the red fireball will go up the trapdoors.
5S 1W
Click here to view the secret text
×Movement order of goblins are weird. IIRC, they prefer E over S which is why it is moving that way. I need to keep an eye on the colour of the tile the goblin is on to know which fireball it slides down during each of the 3 parts. If the goblin is sliding against a fireball, I need to make sure there is a fireball to the east of him going NE so that it doesnt attempt to move onto the goblin and rotate onto the NW pressure plates.
I'll see if these work later, but basic point is, I like how the solutions work out and how you really have to analyze the situation. Hold looks good as is. If the rooms have been proven to be beatable, I reckon it's ready to be submitted. Besides, I know mxvladi is eyeing this.