I kinda like the idea of reducing the distance between the uprights. When kickers are making 85% - 90% of their FG attempts and 100% of their PAT attempts on the season, it's too easy. Another solution might be to have Brad St. Louis snap for every team?
The problem with the varying point values for FGs is that you penalize teams for progressing downfield, unless you allow them to purposely back up on fourth down to make the FG attempt longer. Otherwise, a runner with open field in front of him and his team needing 3 points to tie would have to lay down so as to keep the FG attempt long enough to be worth 3 points. But it might work to just let them pick their spot on the field when attempting a FG, so as to earn the desired number of points. Hey, it works in basketball.