Speaking of the clipboard, this would only take effect if you've copied the information to proceed a transaction, correct? So if you make a mistake, you'd already know that it's compromised, and it won't affect other wallets because you'll be more careful next time. You might even end up reprogramming your computer to eliminate that malware. What I'm saying is, you will lose the balance of one of your wallets but the others will be safe.
This is correct except that the clipboard hijacker malware doesn't affect the wallet itself so it can't steal all your coins. What it does is just changing the address you are sending to with the address of the attacker. You will lose only the coins you are intending to send not all the coins on the wallet.
The safest thing to do is to always double or even triple check the transaction details before clicking the send button.
The more intelligent malware now even try to hijack the clipboard with an address much closer to the address of the original receiver. Mostly first & last 2 letters are same which is all most people look at. So better idea is to check the whole address before sending out the transaction instead of just checking first few digits. I even saw certain mobile wallets show just a few letters of the receiver address on the confirmation page, I had to go back in the mobile app just to confirm the whole address. But yes only the coins being sent out are under risk.
But I had another question. If I can do another transaction with full amount of my wallet (including the balance I just transferred) before the first hijacked transaction is confirmed. Will I be able to do the transaction, let's say if I put a fees to make it possible in the immediately next block?