Last time I opened a channel in Electrum, the remote node set a minimum of at least 0.004BTC.
But take note that lightning and on-chain payments are separate; you can't pay a bitcoin address with lightning nor pay a lightning invoice onchain.
So, depending on your goal, this may not be the solution for you.
But your channel needs "inbound capacity" to be able to receive through lightning.
You can see that in the 'Channels' tab as the "can receive" note above it.
One way to gain inbound capacity is to utilize (reverse) "Submarine Swap" which you can access in 'Channels' tab's setting icon. (maintained by a third-party)
That will transfer your outbound capacity to your on-chain funds, by doing so, your channel will gain inbound capacity from the sent lightning funds.
2. N/A
3. N/A
4. Yes, you can set a different fee slider or even set a custom fee/fee rate of your choice, just enable "Edit fees manually" to have the freedom to manually edit fees.
You can find that option in the settings icon (upper-right) in "New Transaction" window after clicking "Pay...".