A few questions.
 

-It seems that even though I have the "Minimum Time Between Posts" set to "60" people are still able to spam quickly. Is there a setting that would be disrupting this? (I have double post prevention installed)

-Can you allow thread titles to always be editable? Besides just making the time out really high? Also is the title edited when you save in the advanced editor or only when you double click the title?

-Can you prune guest/deleted user posts? I didn't see the options to.

-Any quick option to ban a user and delete their posts? Besides the "Delete as spam"?

Don't think so really. There are some spam mods you maybe want to check out adn see if you can install to your copy of vb.

I think all you have to do is put in a 0 (zero) in the space, but I might be wrong, give it a try. Normally if you want to disable something in the admincp in the options area that is what you do in the space.

Set your usergroup permissions to not allow guests to post unless they are registered. This is the ONLY way to combat guest posting on your site as spam.

There is a quick ban hack that you can install into your vb forum. you may want to do a search for it in the mods section.