Peppercorn sauce all the way. Nearly half the enjoyment of the meal comes from the sauce, for me personally. With regards to burgers, never considered a steak one: most of the time I go for chicken, as normally that's the only alternative to hamburgers - which I don't particularly care for.
I've tried that. I like putting a lot of seasoned salt on my steak before cooking it and some during and pepper. Maybe some barbeque sauce or tabasco afterwards but not too much. I wanna try a steak burger, don't think I've had one of those.
7 minutes is too long for me. Just put some butter/oil in a frying pan, bump up the heat so that it's smoking hot, then two minutes on each side. Obviously more if you like it more well done, but I did it twice yesterday, and it turned out great! There's stuff with seasoning and whatnot that could potentially screw it up, but the cooking part really isn't that complicated!
I've only grilled steak a few times but I've found oven roasting is a lot quicker and simpler. You heat up some cooking oil in a skillet and cook the steak in it for 90 seconds on each side then throw it in the oven at around 350 for 7-10 minutes.