"None" Topic should be an option, and is slow to load

I don't understand, and currently don't like the automatic generation of the "None" topic. For one, it should be delete-able like all other topics. I don't have any use for it, and I don't like topics visible that I will never use. Further, it is extremely slow to load the list of emails that don't have tags. It's so slow, in fact, that until today I didn't believe it actually loaded anything at all. To some extent, I think the "All" topic is equally useless, but I understand that it is meant to undo a search for any particular topic. Perhaps check-boxes next to the topics would prevent the need for the extra "All" and "None" topic, as well as adding a quick ability to search for multiple permutations of tags.