The only weak spot on the venus is in the fuse just behind the wing trailing edge as maynard said.
I have built 4 venuses and found i could reinforce the fuse just behind the wing from the INSIDE of the fuse using forcepts, or hemostats and a little patience.
I have templates for doing just that. This weak spot only affected landings.
Once that is fixed there are no weak spots.
As far as flight, you can do anyting to this model and it will stay intact. I have a couple thousand flights on Venues and have done every concevable manuver with intensity.
I have an OS 120 AX on the Venus which is a very powerful motor for this plane. Still no problems.