> Is there any reason these are actually okay? 

The UniformDeviate ones are ok, since a UniformDeviate doesn't have any options to change.  On the other hand, it's not bad to make a new copy either.

> * line 305 in lensing.py

For this one, it was probably a bug before your recent change, since the code is expecting gd to have sigma=1.  So if you pass in a GaussianDeviate with sigma != 1, it probably did the wrong thing.