The good news is, that's not a house rule. It's the way uncanny dodge works. (I assume "UC" is a typo for "UD.") Uncanny dodge only protects against being flat-footed and invisible attackers (and thus arguably, but not certainly, other attackers the character can't see). All the things you mention involve losing Dex, as far as I know, which is distinct from being flat-footed.It's a houserule, but in my group UC does not protect from anything that leaves you w/o dex to AC other than surprise, invisibility, and the like.
The good news is, that's not a house rule. It's the way uncanny dodge works. (I assume "UC" is a typo for "UD.") Uncanny dodge only protects against being flat-footed and invisible attackers (and thus arguably, but not certainly, other attackers the character can't see). All the things you mention involve losing Dex, as far as I know, which is distinct from being flat-footed.
In rogue versus rogue fights, victory goes to the -- wait for it -- "feint" at heart!
Does uncanny dodge protect a character from losing his Dexterity bonus to AC to a successful feint?
No. Uncanny dodge doesn’t protect you from all situations that would deny you your Dexterity bonus to AC. It only lets you retain your Dexterity bonus if “caught flat-footed or struck by an invisible attacker.” A feint doesn’t render a target flatfooted, it just doesn’t allow him to use his Dexterity bonus to AC against your next melee attack made on or before your next turn.
Since uncanny dodge doesn’t prevent you from being flat-footed, does that mean that a rogue can use sneak attack against a flat-footed character who has uncanny dodge?
No. Rogues don’t get to use sneak attack because a target is flat-footed, they get to use sneak attack because the target is denied its Dexterity bonus to AC (italics added), which is a normal side effect of being flat-footed. A barbarian (or any other character) with uncanny dodge retains his Dexterity bonus to AC when flat-footed or struck by an invisible attacker. Therefore, being flat-footed doesn’t render a foe vulnerable to enemy sneak attack.
Does uncanny dodge make you immune to feinting in combat?
No. If uncanny dodge said “you never lose your Dexterity bonus to AC,” the answer would be yes, but that’s not what it says. Uncanny dodge allows you to retain your Dexterity bonus to AC when flat-footed or struck by an invisible attacker. Although a feint creates a very similar situation (by disallowing the defender from using his Dexterity bonus to AC), it doesn’t specifically render the character flat-footed. (For example, the target of a successful feint still threatens the feinting character.) Thus, uncanny dodge wouldn’t negate the effect.
The good news is, that's not a house rule. It's the way uncanny dodge works. (I assume "UC" is a typo for "UD.") Uncanny dodge only protects against being flat-footed and invisible attackers (and thus arguably, but not certainly, other attackers the character can't see). All the things you mention involve losing Dex, as far as I know, which is distinct from being flat-footed.
In rogue versus rogue fights, victory goes to the -- wait for it -- "feint" at heart!