About selecting tags, are you using the new create entries page? It's still in beta, but very complete. I've been using it for years, so I've forgotten what the old create entry page is like.

But on the beta create page, there's a button under the tag box that says "browse". That brings up all your tags in alphabetical order & you can choose as many as you want for the entry by ticky boxes.

You can turn on using the new create entries page at Beta Features.