Your Jog rate should be whatever your max rapid speed is ie whatever the cvelocity is in motor tuning. You may not see these speeds when jogging if your acceleration is set low and you are only moving short distances as the axis will never get up to speed.
Could be a few things, if you are moving two or more axis at the same time then it will move so as not to overfeed the slowest axis, what you will see for a feedrate will all depend on the difference betwen the distance that you are needing each axis to move to get to the destination at the same time.
Just click OK and it will reset the Abnormal condition into a Normal condition. That feature is the one thing in Mach that I really dislike, it strikes fear into the guy thats new to Mach, kind of like the messages that pop up in windows that say are you sure you want to do this
Hood