Hey Bitten, Good to see yer gona run the BME.
Here's my take on your questions; The plastic reedblock shown will cure the issues of fuel puddling and make the engine run good. I have one and it does work. Only drawback I found with it is it will compress a bit and need to be retightened a couple times. It does quit compressing after a bit and not need further maintenance. It can be improved and mine is by continuing the venturi down into the chamber a bit, but thats a bunch of work hand shaping aluminum to fit. Worth it in a sort of why not way. If you decide to use the aluminum one instead, keep the plastic one because it is lighter.
The WGA 9carb is my prefered carb of the two BME offered. To me it has a smoother mid range. However the WB 35 is a much shorter carb and will fit smaller cowls better. The difference in how they run is barely noticable. One thing I strongly recomend is having BME install a pulse port fitting directly centered in the pump chamber if your carb doesn't already have it there. This will give it the strongest pump action and most consistant fuel metering. Only pay extra for the WB carb if it will help keep you from having to cut the bottom out on a cowl for the carb to fit. It's about 1/2" difference. In my reedcages I drill a tiny (wiresized about 15) hole where fuel could puddle. That would be to the backside as the engine sits in the plane. That lets the fuel suck back into the reeds and go where it belongs
Run the Falcon till it dies. I've had three, the two that died would have a cold cylinder at the start and would slowly come on and run fine all day. So they don't just quit. By all means get an RCXL to have handy as a back up.
Now if you want light, keep that plastic reedblock, find a good SDC 19.05m carb, get a 80mm 8x1.25 Titanium stud and weigh in at 3.9#. Thats light!

Good Luck!