Let's say that I was in a party, near the end of a level, and I spot a rare material or item on the ground. If everybody else and myself decides to leave the group and go solo, will that rare drop still exist for everyone?
Also, if I was going solo (let's say it was on a tier 3 construct level w/gremlins) and spotted a rare drop (let's say a darkfang shield), would I be able to invite friends, then kick them from the party so that they would be able to receive the rare drop as well?
Once something has fallen out of a box, the game has already decided who gets it. If it is decided that you are the one to get it, when you go solo or are kicked it will follow you. As for inviting people, I don't know if that causes the game to reconsider or not.
Intentional or not, because drops do not replicate on party splits prevents an exploit to farm infinite gear by simply being invited then going solo and then inviting someone who will in turn go solo etc. (not sure if this would cause the new party to be restricted or not)