it's tough for me to do much mid-week, so I don't know if it would be a problem leaving it in primary a full two weeks?
It's not a problem at all. I think you'll find a lot of people here (including me) whose primary regularly goes 4 weeks. There's no harm in that and I've found it to be beneficial.
as for "astringency" I honestly have no idea.
Astringency is an easy one...it's a dry mouthfeel, like chewing on a grape skin. If you've never done that, go get some grapes and try it. Many people, however, tend to confuse bitterness with astringency. 2 completely different things.
There are several people here for the Seattle area. Shoot a PM to Tom Schmidlim (tschmidlin here) and ask him.