Thank you.
#1: Fixed, thank you.
#2: Thanks - I've unpublished all my albums, which makes them a little more secure. But it's still possible for someone to try the direct URL to each folder in the path of one of my images and stumble across one of my unpublished albums. So I've experimented with passwords again, and I still think it's not working properly. If I set an album-level password, then that allows me to access the album, but if I then drill down to an individual photo I'm then asked for another username/password, and no combination works. And, as before, if I then remove the password setting from the album, I'm still asked for a username/password for any image that I attempted to view while the password setting was active.
#3: the gallery name and description fields are blank. Nothing in the debug log. I'll try to find the PHP server log to see if that helps.
Yes, I'm using the free hosting offered by x10hosting.com, while I figure out if private hosting is the way to go (given that my main objective is to be able to create URLs to my photos for use in a forum, and which won't be removed or suddenly start costing me hundreds of pounds per year for the privilege). Signing up for a paid service, on the off chance that it might fix a problem with the software, would be a last resort. I may well sign up to a paid service once I know if this is the way to go, but in the meantime I'd like to try and iron out all the bugs, or at least trace what's causing them.