Hi
Cant comment on 1 or 3...but on point 2...
What I have found with the Halkey Roberts inflation valaves, is that
the pump tube needs to have a tight seal when you twist it onto the valve.
If the rubber washer at the base of the adapter on the tube isnt tall enough, it wont seal properly when pumping. Its quite easy to fit an additional rubber washer on top of the other one, and make the seal tighter.
Hope this fixes the problem...