I joined a duplicate bridge group and was matched with a partner; we are doing pretty well when it comes to points. Question: My partner sometimes criticizes not only me but also opponents, sometimes offers unsolicited advice, and is sometimes catty about other people playing in the room. What is correct way to address this? It is not constant an often subtle. Am I being overly sensitive or is this something that should be addressed by me or by the director?
It's tough for the Type A personalities so often attracted to competitive games like Bridge, but all criticisms of partner should be reserved until after the match. I suggest noting to your partner "Make a note of that hand, and we'll discuss it after the game." One or two violations per game, that accept such a comment with a positive attitude, can be tolerated in a partner - any more than two you should be looking for a new partner, as the problem will get worse not better.
All criticisms of anybody else in the room are out of bounds - give your partner one warning and then have a word with the director. If you partner persists in this behaviour during the game look for another partner, and report offenses to the director as they happen by calling him/her to the table. Otherwise you are liable to get branded by other club members as a cohort of like mind.
This behaviour isn't acceptable, but it's not really your responsibility, particularly if you're relatively new to the club. If you're feeling brave, you could mention it directly (and privately) to your partner, perhaps over a cup of coffee. It may be that he or she has gradually fallen into bad habits, and genuinely doesn't see anything unusual, in which case a newcomer's viewpoint would be welcome. It may be that simply saying "that makes me feel uncomfortable, so I can't concentrate on the cards" offers a way for both of you to save face.
If you don't feel like doing that (and I reiterate that as a newcomer you should not appear to tell others what to do) speak to the director, or a committee member, privately. Again, a cup of coffee before or after the session is the best time. It may be (though unlikely) that this sort of behaviour is tolerated, in which case you either adjust or find another club; but at least you will know. More likely, a quiet word from somebody your partner respects (old friend or doyen of the club) will be in order. Even if it doesn't work, you have made it clear that you object to bad behaviour, and won't be tarred with the same brush if you wish to find a new partner.
For what it's worth, this has come up at my club more than once. One person was grateful for a warning: one was too set in his ways to change, and now only plays with an understanding partner and is restrained by the director from criticising those who will take it badly: and one decided that (for that among other reasons) she would give up playing duplicate. Make of that what you will.
It's basically "out of bounds" to criticize anyone in public at bridge. This applies particularly to your opponents. Nor would anyone reasonably want to do so (other than for ego purposes) because it helps the opponents play better.
Any criticism is best reserved for "in private." A partner has the right to express "reservations" about your play (or vice-versa) when the two of you are alone. That helps the two of you play better.
There is one situation where you need to "call out" your opponents, that is not "criticism." If you honestly believe that they are improperly "signaling" each other with voice intonations, body language, etc., or otherwise cheating, the person to bring it up with is the tournament director (the host in an informal "home" game), and let the "authority" warn or discipline the opponents.
As about what to do about a partner that criticizes people in public, give partner one or two warnings (in private), and then speak with the tournament director if this doesn't work. Basically you want to stop, or disassociate yourself from this behavior.