1. Don't visit website with http link which is not a secured connection, a secured one should be in https format.
There is absolutely no good reason to not have
HTTPS Everywhere installed in your browser and running at all times. If you are using Firefox or Tor (which you should be), then you can also just go to Settings -> Privacy & Security and check the box for "Enable HTTPS-Only Mode in all windows". But as DdmrDdmr says, this encrypts your communications with your destination, protecting again interception and man in the middle attacks. It the destination you are connecting to is malicious, then your communication with that malicious site will be encrypted, which offers absolutely no protection to you as the end user. So in short, you should always use HTTPS, but it doesn't guarantee security by any means.
2. Don't make crypto transactions on your PC I find phone to be less prone to malwares
I've stopped running wallets on windows OS pc the risks you go through every day by day is high.
Well, your issue with PCs is a Windows problem rather than a PC problem.
So is it possible for you to copy and paste a btc address ready to send and the cliipboard malware changes it... but if you copy and paste a btc address to say notepad or address bar on chrome ... and it doesn't change it?
There's no inherent reason that malware couldn't detect where you are pasting the address and selectively change it based on this informaiton.
Also what if it looks like a btc address but it has much less characters or more characters? Could the clipboard malware recognize it such as okay this is over 80 characters long... this is not a btc address?
Absolutely.
Also I keep hearing about only btc and eth when it comes to the clip board malware attack. But what about other coins though? Imagine you had some coin that is worth little and most people haven't even heard of. What happens there?
There's nothing stopping someone creating clipboard malware for any coin in existence.