1.) How can it be that some teams are so bad for so long? I mean, considering every year they have the chance to pick the biggest talent in the draft because they are awarded the early picks, how can they be unsuccesful for so many years in a row?

Bad management, mostly. The draft is a crapshoot, too, so just because you have a high draft pick doesn't mean you are guaranteed to pick the best player.

2.) Coming from Germany, I've had my fair share of experience watching soccer. However, recently I started turning away from soccer because, in my opinion, the referees have far too much say on the outcome of a game, with wrong decisions being a daily occurence - many of these wrong decisions eventually decide games. And the FIFA is too stubborn to change some of the old systems in soccer, for example they are refusing to introduce the video proof, etc. However, in American Football, I recently discovered that the referees often ignore very obvious fouls like Pass Interceptions interference and other stuff. How does that come into being? I mean, there are so many referees on the field, and sometimes even I as a Football-Newbie can say 'this was against the rules' without having a detailed knowledge about the rules of the game - so why are there still so many missed / wrong decisions in the game?

Football is very hard to officiate with 100% efficiency. Plays are generally over in 7 seconds and fouls occur on every single play. Calls like pass interference are also left to the discretion of the referee unless it is especially bad, so that is often left to each ref's personal judgement. No matter how good a ref is, there will always be human error.

3.) Not so serious, rather a question because I liked the guy - what happened to Tim Tebow? I know that the Broncos got Peyton, and his stint at the Jets wasn't that succesful, but how come nobody wanted to give him a real chance?

He only wants to play QB and he never will. Julian Edelman (WR), Denard Robinson (RB), Michael Robinson (RB=>FB) are just a few examples of guys who were solid college QB that extended their careers by switching positions. There is also the factor for Tebow that is his polarizing nature, which brings a lot of unwanted attention to teams but is great press for his new job in the media.