That is a great camera, don't let a little set back like this discourage you. My 6X7 does the thing where I have to keep firing it until the paper is all the way over to the take up roll, then dry fire it with the door open to get the counter to reset, it's kind of a drag, but I do plan to get it fixed come winter. Yes it does it with 120 or 220 film.
As for the battery, the camera WILL work even if the battery test light does not light up, I know I shot one roll of film that way. I checked the battery and it was good so I loaded the film the night before I wanted to shoot, I was new to the camera so the next morning I did a battery test before shooting, and the light did not come on. The meter worked, the shutter worked, and I replaced the battery after that roll of film, but I was worried the whole time. I think Pentax did this for safety so there is some life in the battery when the battery light says dead, that way you don't end up with a roll of film stuck in the camera. I check the battery every time I load film, and if the camera sits for a few days with film in it I check before shooting. I will probably kill the battery with testing before killing it with the shutter and meter.
Enjoy, the 6X7 is a great camera even if you won't be sneaking up on a flock of birds and taking several photos with it, K-Thud.