Hi Barry,
A couple of things come to mind from your replies, more "Food for thought" than anything, but here they are:
1) With regards to leaving the standard comment on the menu... why? Here's what I'm thinking. Assume that this is all finished and added to the VBAX cool tools page. You have a user that downloads your add-in (intentionally) because they are interested in it. If your defaults are set to match the standard comments form, why have a duplicate menu item? You could certainly code this to only nuke the default comment menu item when your add-in is loaded, and remove it when your add-in unloads. (Most of that process already exists in the code above... it's just getting the part to delete/re-establish MS's default.) I wouldn't advise this at all if your work didn't entirely match the default's functionality, but it does. I'd be curious to know what others think on this as well.
2) On the point of allowing the user to set the default and read only status... the two could conflict. If you want to store the defaults in worksheet cells, well... you wouldn't be able to save the file. You could use registry keys to store the defaults, however, and I have some code to do that as well, or there is a KB Entry here. One reason this isn't a preferred method, though, is that if a user uninstalls the add-in, those keys could be left behind if you don't create a reliable procedure to remove them. I'm not a big fan of leaving garbage in a user's registry as it does affect computer performance. (Of course there are several high priced professional programs who don't clean up after themselves, but IMHO that doesn't make it right!)
As I said, just "Food for thought"!
PS: Just found BrettDJ's colour picker in VBAX's own KBase!