Unpaid tax liens are indefinite until resolved. Once released, 7 years.
You said it was an error though and the lien never actually was filed. At that point, to get it removed, you need to reach out to the IRS and get documentation from them showing this. You said only one of the 3 bureaus has it reflected- This is actually really good news for you, because you will then need to reach out to that bureau with the information to have that removed. it generally takes 30-60 days to update.
Regarding your CC balances: the impact is based on % of the limit used. Under 25% generally has minimal impact, but at 25%, 50%, 75%, and 100% the impact increases. So a usage of 26% vs 24% would have a larger impact on your score. This is why (if you can trust yourself to not run it back up) you should leave an acct open but w/ $0 balance(assuming no annual fees) because if you closed all your accts as paid off, you could end up having a negative impact on your score because your available credit would be greatly reduced(The age of your accts also has an impact, so if you close all the oldest it can have a negative impact as well).
I once had a link that gave a breakout of how various things like a bk, collections, usage, ect impact the scores, I will see if I can find again.