The Zip'O dont look like it is optimized for the F16 ruleset?
Ref: http://www.ventilo.ch/zipo.html

Compared to: http://www.diversediverse.com/rolf/florin/Prosjekt-hard-milk/hard_milk.html
(got to get that one on to the formula16.org website now. )

Optimum crew weight: I dont know for sure. 150Kgs in two-up mode is heavy. Min weight is defined as being able to right the boat. It is a powerful boat, but there is a lot that can be done with the sailplan.
It can carry three persons, but too much weight will kill performance, just like any cat. The newer designs have more volume than the older ones, so they will handle more weight better than older designs.

Except for Paul Alani, I only know of adult F16 sailors (do we consider Paul an adult as well)? Hope I am wrong about only adults sailing F16s!

Where do you plan to sail/race the boat? Are you certain there are events for you to enter with an F16?