Thanks for the comments.
The first issue with regard to uniqueness is a current limitation within the software. Sadly, we do not support an inter column relationship and uniqueness for RegEx, as in your example. We are aware of this, however I am not sure at the moment that this will be fixed in 1.1. Do you feel this is an important feature?
However, I am not sure why it is only generating 969 rows. It could be that the data being generated is too large for your column? By default, "When data is invalid" we skip the row, this is set on the table generation settings screen. If you change this to truncate data, are 1000 rows generated?
I look forward to hearing your response.