Who pays this mining fee? the sender or receiver?
I don't want that the receiver pays any fee.
The sender, since TX fee is determined by subtract total coin on inputs with total coin on outputs.
What if I would accept a transaction within lets say 1 day =~ 144 blocks
Getting a suggested mining fee for that period seems to be not possible.
It's impossible, either from Electrum GUI or console (through function
getfeerate()). Although you could use
https://mempool.jhoenicke.de in order to make manual estimation.
I remember (at least in former times) that even a mining fee of 0 leads practically to a execution with 1 or 2 days.
That no longer seems realistic, does it?
It's practically impossible, unless you own mining pool where you include your own or miner TX.