mmatty

is it possible to commission you to do it super-fast?
[btw, I couldn’t test it, but we’re going to use it with woocommerce, and I’m assuming it will not conflict with the cart and with people registering-when-checking-out. Do you see any problem with working with them together?]

If anyone interested, here is the solution I came up with for the category case (#2 in my list):
On the index page I check is_category()
if it’s true (Im inside a category page) then whenever I have a permalink to a single post page, I would append “?fromCat=xx” (xx being the current category)

In the single (permalink) page I check $_GET[‘fromcat’], and if it exists, this means I have to modify my next_post_link so it will only look in category xx.

Then its pretty much the same for the other things I asked.