Stegonotus cucullatus - bite reaction and behaviour

We've recently acquired a pair of Stegonotus cucullatus (slatey-grey snakes)
from the Northern Territory (Australia) - don't worry, we live in Australia
so they weren't smuggled.

Very little information seems to be available on these snakes, so I have a
silly question.

In all of our books and information found via the internet it states that
these colubrids are non-venomous, however I was told by an - apparently -
respectable source that there is suspicion that the animals are in fact very
mildy venomous.

After being bitten about fifteen times by the female we have acquired, on
two of the bite sites I now have small blisters, which have had phases of
(very mild) itching, burning and stinging.  I am assuming that these
blisters are from bacteria on the teeth or in the saliva of the snakes, or
perhaps teeth are lodged under the skin. These areas where the blisters have
occurred were washed within five to ten minutes of the bites. The bites
which were not washed occurred a day later and no reaction has been noticed.
My other half also received two bites, neither of which resulted in any
reaction other than short-lived mild itching on one site. Her bites were not
washed.

Also interesting to note was the manner in which the snake delivered the
bites. Few times did she strike, and when she did the bites were often slow
and preceeded by mouth gaping. The majority of the time the bites were
delivered she would nose around on our skin for a short period of time until
she found a tasty (or soft) spot, then she would open her mouth, tilt her
head and proceed to gnaw on the area for a relatively long period of time.
After gnawing for some time she would pull her head back, rather than simply
releasing (this is why I suspect the blisters may have been due to teeth
lodged under the skin), tearing the skin, then releasing.

I'm also wondering how many of these snakes are in captiviy over in other
countries. Are they common? I've seen them for sale on some -
non-Australian - site for $7.50US. I was rather surprised at the price
difference, even though the US and other countries often have reptiles
cheaper than us. The pair we acquired cost $350AU - $175US or so - with a
$50 discount since we bought several other reptiles. This is relatively
cheap also, since the only other S. cucullatus I have seen for sale in
Australia was for $410AU ($205US approximately).

Anyway, does anyone else own these reptiles? Have you received any bites?
Did you notice any form of reaction?