Getting some lag when I play, was wondering which settings are best to reduce it

I'm putting the portal in the right spot in the Nether, but it sometimes sends me to a random lava pool instead of right by the end portal

It was a random seed glitchless run, but I didn't show myself actually creating the world. My run will still be able to get verified, right?

edit: Wait isn't there a way to check if it's set or random seed based on how the world loads? Cause I have footage of the world loading.

I use two timers, one for real time and one for in game time. Every time the in game timer updates (every five minutes), it causes a really big lag spike for up to like 10 seconds. Wondering if anyone has had this issue and knows how to fix it?

I just can't figure it out. I find it really hard to see where the dragon's head hitbox is, even with hitboxes being shown. Do you need all of the crystals to be destroyed, or can you do it with crystals still healing the dragon? Also what's the most efficient way to practice one cycling? Right now I just load into a new world, make a portal, destroy the crystals, and give myself a bunch of beds and give it a try, but I feel like there's a better way to go about that. Pls help ;-;

Someone told me about triangulation and I was wondering if I had to do the math myself or if using a triangulation calculator to do the work for me was allowed.

All I have rn is optifine, and isn't that banned/getting banned? My fps is very sub par without it and I'm wondering what I'm allowed to use.