The PAL versions of the game have quite a few differences compared to NTSC. Some glitches have different setups. You can still run some categories with those different setups though and PBs can be submitted here no problem!

Some applications of SRM are possible for sure. I am not able to confirm if everything that has been found so far can be done on emu but I'm sure someone on the community discord server will be able to answer.

You can by changing the recompiler. Unfortunately if you plan on going competitive you wouldn't be able to submit runs that are within 10% of the current world record as it's a game wide rule. As of right now, an emulator run wouldn't be accepted if it was anything under about 9 minutes (actual time can be confirmed by moderators). You could definitely learn how it works with some hands on experience and then see from there if you want to push the leaderboards with official hardware.

This is by far the best tutorial for the kak route in my opinion: It will teach you how to beat the game in under 30 minutes in not too long as well as some of the fundamentals of oot speedrunning. From there you have many options such as the GIM No ACE route or even GSR without having too many hard glitches to learn.

HESS isn't that bad when you figure out ESS position and how to get to it quickly. After that, all you need is to get to lon lon ranch with a couple bombs and a few hours!

The glitchless categories definitely are the less glitch heavy by definition, but those are pretty long categories. GSR is doable without some high level movement optimisations such as superslides. The tricks that are 100% needed don't take that long to get down when you figure out how to look for specific frames you need through pause buffering for stuff like door of time skip, hookshot jump or shadow boss key skip. Fortunately, the oot speedrunning community is very much alive and there are great resources for every single glitch in the game, like simple setups to get the same results every time. I highly recommend joining the oot speedrun discord channel where you will find a ton of links to youtube video tutorials as well as a bunch of passionate people who will love to go through some harder parts of runs with you. Hope you find the resources you need and I wish you the best of luck in your progression!