1.) Ctrl+Alt+left/right arrow. Two things - it jumps to the next edit on the currently selected track (the dark grey track on the left). It also jumps to event fades, so if you are zoomed out you have to be careful that you have jumped to the edge of the event and not just the inner edge of the fade.

2.) Vegas 4 does what you want using the numeric pad: hit 7 or 9 to select the end you want to trim. Use 4 and 6 for coarse trimming, or 1 and 3 for frame by frame trimming. Press 8 to exit this mode.

3.) In Vegas 3 numeric pad 4&6 do this. In Vegas 4 4&6 are for coarse movement, 1 and 3 are for frame movement of an event (when not in trimming mode)

4.) With any envelope (velocity, volume, opacity, pan etc.) if you Click and Hold the left mouse button on a point you can use 2,8,4,6 on the numeric pad to move the point vertically or horizontally. The precision depends on the size of the track (ie the bigger the height of the track the smaller the increments from using the numeric pad). If you click+hold in between two points you can adjust both the points at the same time. If you select multiple points you can use move all the points at the same time.

Hope this helps! I only just discovered the last one just now.... it pays to play :)