The adjustment from flight-level to surface winds depends on the level that the plane is flying at. The most typical levels are 700mb, in which case FL winds are multiplied by 0.9 to get surface winds, and 850mb, in which case FL winds are multiplied by 0.8. These estimates may be superseded, though, if there is other data available that gives a better idea of the surface winds.

A well-developed tropical cyclone will have the warmest temps at the center, so a stronger or developing system will have a greater temperature difference between the eyewall and the eye. I am not familiar with any rules of thumb about how the temperature difference corresponds to intensity, but others around here would know more than I do.

As for 700mb height, typically the surface pressure decreases as the 700mb height decreases, and vice versa. 700mb height generally doesn't tell you anything you can't get from the surface pressure, though it is a good idea to compare the change in 700mb height between obs to the change in surface pressure to see if anything funny might have happened with the dropsonde, causing a misleading pressure reading.