Good points. Here are a couple of other things I've seen more than a few times; as I'm sure all of us do I really appreciate anyone taking the time to contribute to the site, so I apologize if I seem otherwise in pointing out some things that could be done better with little or no extra effort:
1. Phantom or blank Notes pop up if a Note entry ends with a comma, if double commas (,,) are entered between Notes, or if a space alone is entered in the Note field. These can be difficult to root out, so please try to avoid them when uploading a checklist.
2. When adding multiple related sets, please check the Notes to see if they are actually used instead of just copying them wholesale from the base set. I frequently see two problems related to this. First, an insert or parallel set may not use some of the base set Notes. For example, printing plates are typically not autographed and RC is seldom appropriate in insert sets, so there are multiple sets with inappropriate Note and glossary entries. Second, even if the Notes are appropriate they are not always entered into the parallel sets when the checklists are created so the glossary entries point nowhere. If your checklist for the parallel set does not include the YG Note for the 15 Young Guns cards in the 200 card base set, putting that Note in the glossary is just confusing. Please add the Note to the correct cards if known, or when you can't tell what is appropriate for some reason just leave it out so it can be added later by someone with the correct information. In my experience, it's almost always easier to add to the database than to find and correct errors.
3. An inaccuracy report that "John Smith" is actually "Jon Smith" is not always helpful. If the card is not pictured it can be difficult to determine if this is an ERR or UER on the card or if the card is correct and the checklist as entered is in error. Someone else could track this down, but if it bugs you enough to report the issue, maybe you should be the one to determine what the issue actually is.