In the 100's, on the sideline, you're probably going to stand majority of the game. Whether or not this matters is a personal opinion. It's because of the row of dream seats in front - they have to stand to see, so the 100's have to stand to see over them. It's only bad for shorter people. My wife is 5'6 and she was able to see, though any shorter and she'd have an issue. My personal preference is to be as far back in the section as possible so you are elevated to see the whole field. These seats rock for getting out of the stadium without sitting in any traffic.
If you get in the 200's you can sit and you have a better angle for the whole field. On the visitor side the 200's have some 'obstructed view' seats - some are so bad I don't even know why they exist... If you get in the first 12 or so rows you should be fine, in fact if you're in rows 9-12 i think you're under cover. If you go any further up you start having the overhang block punts, and if you really far up you'll be watching the game on a small TV mounted above you. In my opinion the 200's are the best seat in the house, the problem is you have to know what row in what section to know you're not getting screwed. It's also a little further away from the field from the 100's.
The 400's are great if you get really low in the section along the 40/50 yard line. It was a really tough decision between moving to those seats or going to the lower level, they are truly great seats. You obviously aren't as close to the game as you are in the 100's, but they are still great seats especially if you enjoy watching plays develop and really seeing the whole picture.
When you get a parking pass green is the general admission parking pass, but there are two green passes. One is a B3 pass, which is a small lot on the south side of the stadium - you can only park in that specific green lot. If you get a general pass you can park in any of the green lots. If you have an interest in tailgating with other people make sure you get a general green lot pass.