I'm not sure if your only problem is the fast travel from the get-go, or the lagging hitboxes. Or both?
I liked the fast travelling. It's not like it can teleport you directly to the end of the game. You still have to do it on your own first and only after lighting a bonfire can you fast travel to it. I don't see why it would be a deal breaker. Also, I didn't have any of your lagging hitboxes, but I primarily played in offline mode, maybe that's the reason it was smooth for me?
Sorry about that. I dont hate the fast travel, i simply think that walking from one area to other is more rewarding ( like dks1 ).
About the videos, these are the only " bugs " that i found in the game ( happened to me at least 5 times ), but is stopped after i lvled my agi to 100 ( could be a coincidence ).
Sorry for not making myself clear, my english is not that good.