The errors you see will keep populating one by one until the entire thing is correct. You might have an error showing on one part that is caused by another section of the formula. QuickBase does not always do a great job explaining where the errors are.
I don't think you will be able to just remove those and have it work anyway as you said it was not functional before.
ISPICKVAL Is not a function in QuickBase, at least not a listed one.
You are likely going to have to just start over and use that formula as a guide when making the new one. You can try to edit the code you have but seeing as it isn't even originally from or for QuickBase that is probably going to be a nightmare.
Edit: I see now, this is a Salesforce formula. Right?