Guess I'm late to the party here (was a huge pain in the *** to make) but here's my version
http://rghost.net/42325034
I DO use "improper" parts. Crocodile leather (and turtle shells) now has/have a use! At least, if you want a certain wallet or a certain holster (I forget which). Also, "leaves" are now required for crafting items. I'm operating under the assumption that Jason is an idiot and is using that word to mean "the entire plant". So in my mind, he's using the vines and stalks of the various plants for use in crafting. There are many more items needed to craft now (didn't even get into using multiple animals for one item... hmmm...) and you need to pay more attention to the world is you want to make use of it. No crashes for me and it's been tested (as far as it can be at this early juncture). Enjoy!
And here's a companion file that does the following: All weapons unlocked, no free weapons, prices adjusted up or down depending on the quality of the weapon (not easy to obtain), and (here's the fun part) skins/animal parts prices have been significantly increased so that hunting is always viable, almost necessary way to get weapons.
http://rghost.net/42325444
This all might need some adjusting. I'll do it based on my own gameplay but feedback from others can be useful.
Also, thanks to all the modders who figured out these commands; most of the credit goes to you.
EDIT: Oh and, by the way, the numbers for blue and white leaves are switched in the wiki. Blue is 1386 and white is 1385. I also forgot to mention that the number of plants to craft syringes have also gone up (for instance, 3 seemed a good number for basic medical syringes). Um... which probably breaks the crafting tutorial, now that I think about it. Stupid mission areas...