We're 5 players and everyone runs his own campaign, switching weekly. Also, I am in an online campaign.
-What level are you?
Level 4 (Rise of the Runelords), Level 6 (Curse of the Crimson Throne), Level 19 (Savage Tides), Level 7 (I am the DM, H2), Level 2 (I am the DM, Online Campaign, homebrew, starting with KotS elements). We also have a Warhammer 4E campaign, but we have paused it for a while and played Torg instead with the DM, so I don't remember exactly which level. It's homebrew.
-How long do you play for?
My regular group usually starts around 18:00 and the game runs to 1:00 to 2:00 in the night, so around 6-8h. (Of course, with the usual goofing around and making jokes

).
The only campaign is about 2h30m per game
-How many combats do you play?
3-7, I think. Online 1-3 combats.
-How long do they take?
About an hour seems right, but it depends. In my own campaign, since the PCs are a little higher level, I conflated a few encounters in H2 to one encounter, making it a lot longer and harder.
-How many players do you play with?
3-4 players. Usually we make sure that we have 4 PCs, though, so someone has/may run two characters. The online campaign has 4 players, too.
-How long do you roleplay for outside of combat?
Depends on the adventure, I'd say we are pretty combat heavy. About 1-2h per session or so is usually involved with gathering clues, talking to people, making decisions. We don't spend too much time just "hanging around" in-character. There is usually always an in-game goal we follow. (make an ally, find the culprit, figure out the mystery, where can we go next to kill people and take their stuff.)
-Does it sometimes feel like playing a boardgame?
Combat is always about tactics, so in that way, it's certainly like that. In games where we don't need a grid (Torg for example), we still play with a similar mindset, but you don't have to track positions, of course. But there is always some light role-playing on, characters talking with each other or the enemy, narrating what your attack does (but not every attack.

).
One of the fun things is the joking that goes on that is based on the fact that it's a roleplaying game - for example when a player announces his character to be bloodied, the Tiefling player will jokingly consider him as one of the target "hey, he's bloodied, and in this position I'd get combat advantage, too!". You don't usually get these in board games (well, it probably depends on what kind of board game. I could see it in Warhammer 40K, but not in Chess or Checkers.

)
-Do you change any of the rules?
So far, I don't remember any changes. I think I'd ban the Battlerager Fighter in my campaign.
In the online campaign, I decided to give out twice the usual XP. Online we don't have so much time and I don't want to sit around at one level for too long.