Edit: I think I have arrived at the same page where im doing P2P transfer
This is the best/correct way to do it right? This is the way i did it last time
https://imgur.com/a/uNQ0aouQuite, P2P is one way to sell your Bitcoins, yes.
But in P2P, the Bank transfer that the seller supposed to do is out of your and Binance's control so be careful when proceeding on release your Bitcoins.
The danger here is if you've release the Bitcoins and seller suddenly reversed the bank transfer, so make sure to select a reputable seller with good reviews for high value transactions.
BTW, discussion about trading your deposited BTC is quite off-topic to your OP.
-snip-
What would have happened if i didn't set an optimal fee? Could the transaction be stuck for months? I am using Electrum 4.5.5
-snip-Nah, it's just you can't use the accelerator for a cheaper option.
In any case, Electrum automatically opt-in the transactions it create with rbf-flag,
So if ever, you can replace it with a higher fee rate transaction with "
increase fee" right-click menu.