Step over height: i don't know exactly. Must be something close to 65cm (Max height without canopy is 95cm)
Air flow: the hole in the front is for the light and covered by a little pmma screen. It needs to be covered because of the fogging problems.
Below You see the bottom of the velomobile. In the front there is an air intake for an "air chamber" in the nose which acts as the reservoir for a fan keeping the screen free from fog. Which works quite well. This detail is not present in the older GoOnes. You also see the huge foot holes which may act as air intakes - but You don't notice much flow from them. (I think i'll need to refer to this picture as soon as it comes to some of the aerodynamic aspects, but i think I'll also need links to external pics for that).
Front suspension: internally the bike uses the standard technology of the dutch velomobiles (Quest, Strada, Mango) which has, AFAIK also been used in the first Milan's. That means something near 38mm total suspension travel and roughly 50% real. The other 50% act as negative travel under load.
Noise: pretty loud, but an old Opel Agila (Suzuki Wagon R) on the highway is louder. Over long distances, some ear protection is useful, but not strictly necessary. The main source of noise (on a flat and even road) comes from the back: both the large plate with the suspension and the chain idler are audible.