Johnny is referred to as the Gonk, but regardless of our opinion of his actor, wouldn't his character be closer to Informed Attractiveness?
No, because no one ever claims that Johnny is handsome.
Twice in the movie, Lisa says "You owe me one." Once she says it to Mark, and once to Johnny. No one ever explains what Lisa did for either one of them that they owe her one. Was that supposed to be some kind of catchphrase for her, or what?
In Johnny's case, I think it's supposed to be payback for her lifting his mood with pizza and alcohol after his disappointment at not getting his promotion. In Mark's case...um...it may be because she has wanted to talk to him before, but he has always blown her off because he's "too busy."
What the hell does the 'R' in Chris R stand for?
Tommy Wiseau said it is because Chris-R is a gang-member and wouldn't want to reveal his real name, which makes it strange why he doesn't just go for a pseudonym. It is unlikely Wiseau ever came up with a full surname.
This probably wouldn't stand out so much if it wasn't for the fact that "R" is the closest anyone in the film gets to having a last name. Wiseau didn't even bother giving his own character a surname.
In the scene where they all arrive in tuxes, Denny, Peter and Mark arrive in such quick succession that they must have seen each other coming up to the house - yet they act as if they've all just seen each other upon arriving at the house.
Well, I know there's been times when I've approached a house at the same time as a friend, and called out to him without him noticing me, so we had to enter the house separately. So...maybe they're just all idiots.
Why is the television positioned in such a way that the furniture blocks the view?
No one is ever seen actually watching it in the movie, even couch potato Lisa, so maybe it's just there in case someone wants to catch a game or something.
Why does Mark act like he's completely innocent after Johnny's suicide? He puts all the blame on Lisa when he's just as guilty, if not more since he was completely capable of telling her to fuck off in the first place.
He was probably overcome with grief.
Plus, are you really expecting someone willing to sleep with his best friend's wife to be willing to take the blame for his best friend's suicide? Especially since he consistently blames his infidelities on Lisa, it's not like it's out of character for him to pass the buck.
Also, this whole movie seems to be Tommy Wiseau venting his rage on some woman who was unfaithful to him. He probably doesn't see Mark's character as anything but a penis on life support.
If you take the movie at face value, Mark is culpable but not nearly as guilty. Lisa is essentially freeloading while between jobs, she pushes for the affair, she fakes a pregnancy, and she gets increasingly flagrant in her disregard of Johnny. Mark displays at least a little reluctance about his involvement. Still, you're right. It is out of proportion.
Why would Peter even bother hanging out with any of them? In fact, how did they even meet?
Maybe he went to school with Mark? There are a lot of ways this is possible.
Also note the he stops hanging out with them after the tuxedo football scene, so however they met (which, as the above troper noted, could be a lot of ways), it apparently didn't stick
That's more a case of Real Life Writes the Plot, as the actor had told Wiseau he had another acting job he had to do, but they never bothered filming all his scenes.