Regarding achievements where you need 3, 5, and 10 of swords, helmets, etc:
1) Is it the total number of items, or do they each have to be unique?
2) If I craft an item up to it's next level, does the system consider that a new item or still just counted as the original one?
I can confirm that when you craft an upgaded item it gives you an extra count for the achievement. I upgraded my shield yesterday and despite only having that shield and the proto shield I got the achievement for having 3 shields ;)
I don't know if is counting the total number of things you have owned or the total number of unique types of items you have owned (ie: whether 10 caliburs counts as 10 or 1).