I'm wondering about deactivating mods after you import them into a bashed patch, can you deactivate any mod that's been imported or are there certain instances where it just shouldn't be done and if so how do I know when I should deactivate something?
Some mods can be deactivated, but others simply will not work if this is done.
I don't think there is any simple rule for what can and can not be deactivated (I wish!) But as a general rule the more complex files, with multiple types of things going on, should be kept active, while many simple ones can be safely deactivated.
Wrye Bash is a very useful tool here. you can, using the Mod Checker button, check what mods it recommends for deactivation. It is generally pretty accurate in that regard.
And you can always ask about specific mods if you are unsure.