I've just watched a "100%" run on YouTube and in the description it was mentioned there are some unobtainable treasures:
Level 2 - coin being too high to be reached
Level 9 - gold bar inside a crate that cannot be reached
Level 14 - a missing Tiger Guard with gold bar, cross and ring

So, should a 100% run be done without these?
Also, level 2 and 9 can obtain the "Perfect" screen with using glitches, are they still required for 100%?

Thats why the rules list "-100% runs must show the Perfect screen at the end (or the best possible if Perfect is impossible)"

So what are the glitches to beat it 100%, cuz im trying and it would be a pain in the ass trying to do some thinks that i cant even pass without glitches

Level 2 - perform a dynamite jump to get the unreachable coin
Level 9 - pretty much impossible due to the crate with the gold bar being unreachable and there's no known way how to get it so far, besides 4 or 8 coins are missing aswell depending on your game version. The 4 coins are held by a seagull that doesn't spawn until you kill a certain enemy later in the level and as for the other 4 coins, I'm pretty sure their location is unknown.
Level 14 - Getting a perfect score in the level is now possible in the later version due to it being fixed.

you have to glitch your brain into having infinite patience