If I use Connary's BSA version, does it completely replace the visual pack, even if I installed the visual pack first?
If you use Connary's .bsa and it is dated later than the visual pack files, then any of visual pack's files that are the same name as the files in the .bsa won't show up in-game. If you want to pick and choose, you'll have to extract the files from the .bsa and install them normally. The best solution I know of is using Mash's replacer feature. You could then extract the files from Connary's .bsa and place them in their own directory under the replacers directory. Then extract the files for visual pack to their own directory (again under the replacers directory). Once you decide which of Connary's files you don't like, all you have to do is delete them from the directory. Once that's done you use the replacers feature of mash to install visual pack (by checking its box) and waiting for the files to extract. When it's done you can check the box for Connary's textures and they will overwrite the files from visual pack that have the same names. This will give you the ones you want from both packs without having to worry about the .bsa.
That may be a little confusing , so I'll tell you how I use it. I check the box for richer textures, wait for it to extract the files, then check the Connary box, wait for it to finish, then check the boxes (one at a time) for the smaller texture replacers. In the end I have a fully retextured MW with richer textures covering everything that Connary's doesn't and my favorite small retextures overriding both mega packs. It's really easy once you get your head wrapped around it.
KF