Prepping For Database Restoration

I have encountered a “problem” (fussy client) with a site and I will be restoring it back to a downloaded .gz database from two months ago. Now, in my work since then, I’d installed a new theme and created custom post types. The new theme has a number of custom CSS settings, and the custom post types have a number of files.

Since I’m doing a database restore to a snapshot before this existed, I have a few questions:

-Will this restore all setting to how it was configured at the time (general, reading, discussion)?
-Will the plugins that were added later just be deactivated?
-I’m guessing the new theme will still exist since its files are physically there. Will any settings on the new theme get erased with the database restore or will they stay and the theme just gets deactivated?

It’s a messed-up situation and I basically want to restore back to August but archive my work on the new theme and custom posts if possible.