well, you would certainly need a pretty long belt. i would personally not let a belt that was exposed to the elements run inside the timing belt cover, but that's just me. i suspect you would drastically decrease the life of that belt, and to a lesser degree, the timing belt. there is a reason honda put that cover on there with a seal all the way around it.
i will also assume that you're not going to use the jr blower and jr intake manifold adapters. with them on there, there is absolutely no way to get where you're planning on going from the blower - the new belt would run straight through the manifold. you can see that here, if you imagine a path coming toward you from the blower pulley :
it looks like it might be pretty close to making it almost to where the nose of the blower is now. might have to get a longer nose. eaton makes those, not sure if the counterrotation will be a problem. the blower for the rsx has a really long snout, for example.
also, don't underestimate the sheer quantity of crud that is under that innocent looking timing belt cover :
both spin much faster than the engine, not sure if it's 2x or not, but you can estimate from the size of that big cog in front. for whatever reason, the rear balance shaft has a reduction gear in the casing.
if i were doing this project, and not spending a ton of casht o blueprint/balance my engine to the highest possible tolerances, i would desperately try and find a way to do it without removing the balance shafts!