Should they be "General:" or "Character:" tags? Sometimes I see that both possibilities exist. I suppose all of them are perfect and reasonable "Character:" tags, (for starters, they are proper nouns, after all) but I may be wrong.
It's pretty much case by case. Generally they should be general tags unless they are actually a character in their own right, like young Alice. So izayoi sakuya (dog) would be the only general tag out of the examples given.
This issue was discussed in forum #54143 and forum #61895 over konpaku youmu (ghost), and if I recall correctly one of the main issues was these tags messing up the chartags count. However, with the solo and #girls tags, I don't see this as being that big of a deal. There's also no reasonable way to maintain the tag types without watching them constantly.
Personally I feel more of these should be character tags, given that they're tags pertaining to information on who the character is that is depicted. I do acknowledge that would come at the expense of the current chartag search, but I think having that information better labeled is more helpful than getting the chartag search to spit out images of a specific number of characters (which it still will, just with a bit more noise).
There was some talk on fixing the issues with the chartag search in forum #58503, but nothing that would appear at least in this iteration of danbooru.
Rampardos said: Generally they should be general tags unless they are actually a character in their own right, like young Alice. So izayoi sakuya (dog) would be the only general tag out of the examples given.
I agree. I don't think we even need something like izayoi sakuya (dog) if it's not a character in its own right. We have dog and animalization after all.