Potential feats ...
Great Pretender: +2 Bluff, +2 Disguise
Silvertongued: +2 Bluff, +2 Diplomacy
Knock-off Product Manufacturer: +2 Bluff, +2 Craft
Rumormonger: +2 Bluff, +2 Gather Information
(etc.) ... And, of course, the infamous Skill Focus, +3 Bluff
Silly though my examples might seem, I'm using them only to frame a question: How many (hopefully legitimate) feat-related skills bonuses would you allow a player to accumulate in one skill?
Great Pretender: +2 Bluff, +2 Disguise
Silvertongued: +2 Bluff, +2 Diplomacy
Knock-off Product Manufacturer: +2 Bluff, +2 Craft
Rumormonger: +2 Bluff, +2 Gather Information
(etc.) ... And, of course, the infamous Skill Focus, +3 Bluff
Silly though my examples might seem, I'm using them only to frame a question: How many (hopefully legitimate) feat-related skills bonuses would you allow a player to accumulate in one skill?