As for the collectibles not respawning, I also noticed that, but I thought it only came with the patch before Realm of Magic (or at least that's when I started noticing it). A tip for the Collector aspiration: If you can't find any more crystals, fossils etc., just drag the ones you already have out of your sim's inventory and back, or let the sim pick them up again. The game will never know that you've collected those particular items before and will add them to the count. It may seem like cheating, but at the same time it isn't because technically you've already fulfilled the requirements of that milestone, the game just didn't register it.
The collection system as a whole seems to be broken, though. My Lara Croft has been to Selvadorada at least five times and completely raided those tombs of their artefacts and treasures every single time, yet her household inventory still claims she hasn't found any of the collectibles. It's just weird.
