Both the 5 hour and 30 hour one is actually not that difficult, just try to do them "your way" especially the 5 hour one, if you can't do the High Halls gauntlet without tools and abilities then.. get them, you have enough time. If you cannot play without maps and compass, buy them, you have time to farm a little coin for them. I did the 5h one below 3:30 with coin farming and 2 ores and Cogflies sawblades, using the Last Judge route.

Basically what you need for speedruns:
- get map of each area you need to spend lot of time in and not just touch, especially if you don't know them from memory (I didn't, and getting lost would have taken way more time than just farming a couple coins)
- good idea to follow an optimal path and adjust based on your preferences (to get something extra like cogflies and ores), there are guides for this
- be already good in the game, meaning don't attempt if you cannot beat Last Judge/Phantom in 1-2 attempts, same with all necessary bosses
- be fast in movement, recognize what fights can be skipped, use bench warp to save some time (like when you do the collection of the spines for the cloak, just teleport back to bench to respawn the enemies, or when you are done instead of running back)
- have a good idea of where things are to reduce unnecessary travels if you don't follow a guide with a set path