A few questions topic

hey guys i have some questions before i flash my mom international S3 and brick it and then she bricks me LOL i want to return to stock 4.3

1) is there a stock rooted international 4.3 rom which i can flash via TWRP
2) what if i download a rom from sammobile and flash via TWRP will i **** it up or do i have to use ODIN so hate it LOL


for now that all coming in my head