I would also try ntsc to confirm its just pal with the level looping.
Are you using actual analog or did you map your dpad onto analog?
This could actually be your problem, im not 100% certain, but I have always been able to dash while level looping on ntsc without any complication. It may have something to do with the speed conversion from ntsc to pal. Pal runs slower.
From what I remember you can dash easily. Try doing it in haunted ruins right in front of the bridge. I think analog is the main key here. It's either that or mess around with the jump button. It's hard to give you a proper answer without being in game.
There's a door you can take in the area with the last boiler you have to light up. Just take the platform up. I believe the platform works once you flame the boiler.
Everything is allowed, just don't enter the bosses early.
40 dark gem is any% no major skips, which is not skipping into any of the bosses. You can skip the hunter section in icy wilderness btw by going into ice citadel backwards.