I tested my Root Keys for my bitcoin wallet on my online computer. Is their anyway the keys can get stolen when I input them; like if I have a keylogger on my system?
In theory, yes. IMHO, the best practice would be to never let these keys touch a networked computer (for any wallet that is going to contain a significant amount of coins), but instead restrict them only to a permanently offline, air-gapped machine.
but if you want to make a cold storage it will be quite harder to use your coins for buying stuff etc.
If you want JUST to hodl ... cold wallet would be good option.
So what is your purpose? Keep your coins safe of rotate them
spend, earn, etc.