[Q] restoring stock recovery, rom, wiping root topic

Heya,

I need to activate my phone guarantee and wondering what are the steps one might take in order for them to not void my guarantee.
I have rooted the phone, installed custom ROM (cloudy) and TWRP.

On my previous phone, samsung s2, the download mode had a flash counter that indicated how many times I flashed a rom.
On my LG G2, the download mode just says "rooted".

1) So where do I get a stock rom from?
2) Where do I get stock recovery?
3) How do I wipe any evidence of root?
4) In what order do I need to do everything?

I did google and came up with some of these answers, but I put my trust in XDA and hoping I won't f*ck my phone up by doing something in the wrong order.

Thanks!