This seems to come up now and again so I've decided to post what I wrote at AUGI this evening here too...echo echo. Regarding the eternal question, "Can I change the order of the parameters in the Family Editor?"
I wrote THIS POST in November 2007. Scott Hopkins shared a tip at AUGI and the post includes a link for that thread at AUGI.
Parameters are "stacked" as you create them, the "oldest" goes on the bottom, in the group you assign it to. It doesn't matter whether you use alpha or numeric etc...oldest goes on the bottom. If you create several "placeholders" like XXXX, XXX, XX, XX you can create them and then rename them so they appear in the desired order. This assumes that you know what you need and how many as you start out, easier said than done.
Scott's technique will help after the fact. None of these will help when you use shared parameters however...for those you have to "live" with where they land. Naming parameters with common names first followed by differentiators will help keep related parameters together.
Wish it were as easy as "move up/ move down"...or drag to reorder...it should be