Is it normal that firefox keeps crashing when i try to open it ? does it mean it cost to much ram to open? cause other browers like brave(very fast) and vivaldi i can open en run no problem.
Yes. There are some programs that don't work here. The problem is with the kernel and will probably be fixed later.
Is there way to delete apps that came with the rom i can only dissable them forexample the browser?
With root rights, you can delete some apk files. But I do not advise deleting the browser, it is needed, for example, for authorization in some public Wifi networks.
I used all the roms in your page and they all behaved the same in terms of speed even the go variants?
1. In Go-versions, background processes work more economically.
2. The difference is noticeable in multitasking and heavy applications. For example, in Go-versions, the Yandex-map works faster.
3. The transition between regular and Go-firmware has some peculiarities. When installed over the old one - TWRP automatically edits the options of the new firmware by analogy with the old firmware. For the correct transition between Go-version and normal-version, you need to clean up /system /data before installing new firmware
4. After installing any firmware - background cache rebuilding may take several hours. Conclusions about the speed of work should not be made immediately.
however i dont know what happend but i was running 14.1 los and firefox crashed after running it and was playing around with it and i had prevouislly used a stopwatch to test how long it took to open the apps and they al had the same time give or take then i used the batterie saving mode and started noticing the phone got faster?
In saving mode, some of the background services do not work or work less frequently, so the phone is faster.