Ok, as a note some of the things listed here may not technically be 'bugs' but they are problems with walkmeshes, passing through objects, floating things, AI pathing, etc. Just a list of things I made while wandering and trying really hard not to get my character killed (it's a habit from beta testing other games to make a list). Also many of these things may already be known/in the works to deal with... i'm just listing them here because I was told to rather than PM a DM with them.
-> Knights in silver parade grounds: Where the second crossbowman looks is a clipping issue with the wall, two sections overlapping each other.
-> Knights in Silver parage grounds: The large tent staked to the ground is floating on the side closest to the gate, raising the ground here would solve the issue. The red tent near it floats in the back as well.
-> Silverymoon City: Numerous doors are either misaligned or not appearing. Several doors also have working open/close animations but go nowhere. I had a running count of misaligned/non-existent doors for each section of the city... but apparently I forgot to save that
-> Rauvinwatch Keep Farms: Many buildings here can be walked through, as well as the lake itself (though that does at a little RP... if you like swimming...).
-> Blakar Gate (outside): Not so much a bug but worth mentioning; when walking towards the gate you cannot see the guard on the right side as he is blocked by the Obelisk stating SM's population and the gate name, I would suggest moving it to the right a little more (as it doesn't seem logical that a gate guard would stand behind an obelisk obscuring his vision all the time).
->Silverwood Forest (just outside Silverymoon): Near the bottom/right portion of the map at the top of the hill near to the small house is a wall, majorly unsupported by the ground (raise terrain/sink wall to fix). The tower across the way from this wall also stands on three legs, not four.
->Silverwood Forest (just outside SM): Near the bottom/right portion of the map the small house and the outhouse (i assume that's what it is) have working doors which lead to no interiors.
->Start Area: The 'fur cloak' for 15gp in the start area shop does not form to any of the races i've played (human, halfling, half elf). It always appears halfway up the characters head where it should be flush to the shoulders, and this also creates a clipping problem where it shows a portion of the players back through the cloak, which just generally makes it look bad (though I really wanted one!

).
->Silverymoon South District: The house directly to the right of the statue in the glittery water, is floating about a foot or two off the ground.
->Silverymoon South District: To the left (coming OUT of) the Silver Guard Fortress Doors, behind the theatre and a house with a guard in front of it, is a house which is floating some several feet off the ground.
->Silverymoon South District: The sewer entrance north of the Fochlucan is floating a bit and it isn't back against anything, so the backside of the entrace is visible, which makes it look.. unrealistic (for lack of better words at the moment).
->Silverymoon South District: Near the glittery water and statue, the house to its immediate right (the statues) has a Commoner NPC who seems to be stuck at one of the corners of the building, as if his path tries to take him somewhere through the buildling so he keeps wandering back and forth at the corner. (I have only seen this once so far).
->Silverymoon South District: Near the 'Stonestorms Harpery' sign (which doesn't have a working door/interior) there is a mouseover of 'Mrellow Lane' in the middle of the alley that just mysteriously appears. No sign is visible nearby to display a street name, so all I can think of is that the sign is under the ground (or simply not showing up for me).
->Silverymoon, Vault of Sages: When you get the token to view the upper level books, if you venture to near the exit (near the steps up to the door) it will dissapear. Also when I went down one of the wings which are past the door it dissapeared from my inventory as well, though this only happened once and I haven't been able to get it to reoccure. (by dissapear i mean 'crumble' as it is supposed to). I realize this isn't an actual 'bug' but to me the range in which it crumbled was a bit much, though I can see why it was done this way.
->Silverymoon South District: At the amphitheatre thing (left off the bridge, huge ladies head, seats and a stage), if you head to the back you can see the water between the land and the seating.
->Silverymoon South District: The left tower off of the bridge has a walkmesh under it, aka you can walk through it.
->Silverymoon Northwest District: A section of the terrain 'on top' of the Bright Blades Brandished (where it's all jagged) has a funky walkmesh which you get caught in easily.
->Silverymoon Northwest District: The housew ith the purple roof, across from the 'Abandoned House Entrance', has a section in that small alley where it can be walked through, enough to completely hide a PC.
->Silverymoon, Providers Shrine: Was made for halflings........
->Silverymoon Northwest District: The city wall directly north of the Hammer & Helm, if you go behind the houses you can walk through most of the wall, and even onto the other side at some points.
->Silverymoon Northwest District: Between the Optym's Blade/Feathered Ash to the north (near the city wall) there is a building (church looking building with the tall,pointed red roof tower section) in which you can clip through the entire back half of, but not the front.
->Silverymoon, Golden Oak Inn: A portion of the wall (right of the armoire, looking into the room) in chamber 2 of the Atrium, can be walked through from the hallway behind it.
->Silverymoon, Golden Oak Inn: Brennegan in the Tavern under the Golden Oaks doesn't present you with a "menue" when the option is selected. (no store screen)
->Silvermoon Pass, Hawks Nest: In the 'village' area (the walled in place with several buildings) to the north, in order to reach the large hall and two houses in the back you have to pass through a pile of crates/baskets/etc that block the way (though you can still go through them). As well several 'static' items under the tent here can be walked through.
As I explore more area's (and eventually die... it's gonna happen) I'll try to make the list bigger. Also if you need clarification (as I know i'm horrible at explaining things sometimes) just ask via PM or IG via whisper/tell and i'll gladly help you find the buggy spot.
[NOTE:] I tried to avoid listing things that are unavoidable using the NWN2 toolset, such as objects on hills being flat and not flush to the terrain, which leads to an 'invisible' inside of the object. Though some largely bothersome instances of this may be listed.