Graphics don't matter as always If you don't wanna speedrun Minecraft with shit graphics, accept it.

Resource packs won't affect performance unless putting from 256x to 2048x pack.

For potato pc, use jellysquid mods, reduce render distance and set everything to low and fast.

It is allowed via pre 1.9

Because of your computer being shit or whatever, it might be likely bottleneck or drivers, so you'll have to match current cpu + gpu in order to lessen bottleneck, or just update the drivers if there's working

If not then try messing with memory allocation. I don't know how to help you but hope it works.

Because more updates = more features thing? I dunno

also it should be work without mods (except jellysquid so get a new computer if u don't want optimization, except cries in broke)

Well then use JellySquid or just Vanilla for speedrunning and use some good FPS optimization clients for PVP

Protip: get a new computer lol (cries in broke)

Doesn't matter tho No matter how age they are if they're competitive at them, try and play it.

Some speedrunners who are underaged like Korbanoes have already submitted their speedrun before.

I mean, for recommendation, just buy Minecraft. Though unrelated reply, for my Philippines, I've found some Minecraft game with "full-access" via Lazada and sometimes they went out of stock. Not sure if these products seems sketchy.

I wish Mojang will add official minecraft in Philippines

late but yes you can just in case you don't want using a keyboard occasionally