I agree with the general distribution of stats (Higher ST and PS, lower SS and PT), though I've yet to decide just where they should lie, now given Harvest.
More often than not, though, I'll hedge on the side of higher on Stat Limits, and tailor a spread to submit over the coming days. Give people flexibility.
That being said, Fantastic is the max needed. Amazing is pushing it on ST.
On PT, spreads maybe should be Below Average, I think offering Above Average is acceptable.
SS should be capped out at Below Average, though it very well may end up Poor or Bad.
And finally, PS I think needs to be in the Very Good range.
Basically, what Deck said. Though I wouldn't say Fantastic is necessary on ST. Only that it should be allowed. Harvest is a potent ability and Excellent may well suffice.