The Raul quest, I had to trigger through the console. One of the triggers, if you fully interact with that trigger before you meet Raul, you will not be able to interact with it again. The biggest problem is that the main story will most certainly guide you to reach that trigger first, before you meet Raul.
Spoiler If I talk to Ranger Andy and exhaust the dialog, when I go back to Novac with Raul and I try to talk to Ranger Andy,
my view kicks back to a camera only view (can't see my hands/weapon, can't go into 3rd person), and my character loses collision, just floats like a ghost and can go through walls.
There are some other broken quests, but the one that really bothered me was during the NCR quest, which is flat out missing dialog triggers for mission objectives. .
Spoiler When the NCR sends me out to deal with the BoS, it gives 2 options: kill them all, or ally with them. If I want to ally with them, and during the BoS quests I help Paladin Hardin become Elder, I cannot ask him to join me in the Hoover Dam battle.
. And I looked all over the dialog tree. The dialog is just not there.