Steering in pivoting boom front wheel drive recumbent bike
I've built one and ridden a couple of commercially made ones (Cruzbike and a European one) and I have not been very impressed. That design has never done very well at our local races, for example.



That's the prototype we built that convinced me it wasn't a design I wanted to go further with. It was quite rideable but there wasn't enough great about it to make it worth choosing that design over something more conventional.

As far as slalom racing goes, you'll obviously be trying to build something lower and more reclined than I did, possibly like the CruzBike RAAM bike. I think it will be worse in the slalom than a fixed bottom bracket bike because pedalling while turning is harder, and at sharp turning angles is impossible. The main problem is not so much the funny angles between the pedal and your ankle, but that the inside leg is pushing out on the steering, while the outside leg is wrapped around the bike and pushing in. That makes pedalling in circles basically impossible so it is very hard on your arms (and the handlebars have to be beefed up to take the extra forces).

There are a lot of recumbent designs out there, even if you limit yourself to two wheels. I suggest looking around the homebuilder sites and maybe going to a traditional highracer style SWB bike. The RAAM CruzBike is effectively a highracer, but a steep seat one rather than laid back. Those are pretty easy to build and do better in slaloms than the really low lowracers do (higher CoG means there's less mass moving around the slalom cones).