Kerbal Space Program – Do You Need to Start a New Career After Installing Breaking Grounds Expansion?

I think the simplest way to do that (and that's how I usually do) is to use MechJeb with the "land at target" function from orbit. Usually, if your lander is well balanced and not too creative with staging, is quite accurate. One time I actually landed on a previous lander while AFK.

In any case, you can use MechJeb to time the deorbit burn, and then fine tune the landing manually.

If you really don't want to use autopilot, yes, maneuvers nodes don't account for atmosphere, so on Kerbin aim to overshoot your target. Actually, you have try to overshoot your target in any case, because if you don't want to land "Jebediah Kerman style" you're going to brake hard to kill your lateral (first) and vertical velocity before landing.

If you look carefully, you'll see numbers on the reputation bar. It sounds to me like you're in the area of 700-1000 reputation. The pin in the middle of the display corresponds to your current reputation. As you gain reputation, the background moves to the left, and you enter the green and blue zones of high reputation. At the start of the game, you'll have 0 reputation, and the bar will indeed be green and yellow.

The striped blue area on the right is reputation over 1000. I don't know if it's possible to pass that. The areas corresponding to less reputation are to the left, and get progressively yellower until you go negative, at which point it starts to become red. (I haven't played in those areas yet, so I don't know much about it :P)

The purpose of reputation is to affect what contracts you're offered. I suspect the color zones on the reputation bar represent different 'levels' of contracts. I haven't tested this though, and the colors could be purely aesthetic.