I see that this tool does not give anything without entering your own address or email.
They don't display ads, so they can profit by selling data.
Will they try to sell this information in the future, or will they not publish the spam to my email?
Why do I need to enter my ETH address to get an airdrop or get notifications in the future?
That's paranoid but ok. Email is nowhere to be required unless you want to be notified of new airdrops.
Regarding ethereum address, how would system know if your ether address is eligible for airdrops if you don't enter it in first place?
Do you have to hold the same amount of ETH to receive airdrops? I got like 15 cents worth of ETH but am not sure if it would be worth claiming those miniscule airdrops.
Yes, you have to make a claim transaction and with current gas fees in mind it needs like $40 minimum in eth. Don't claim unless you know it's worth it.
Is this only for the Ethereum network or can I enter the BSC wallet address?
Only ethereum.