Ambrose Guardians have a chance to drop one, and once you have access to Ambrose City, there's a shop that sells more and will buy any extra.
There are three optional Maids - one's in Adhauga, one's in the East Swamps region map, and one's in the Ambrose Estate kitchen.
Yes, it's possible to lead the Order, though it's difficult. The vote is based on all sorts of criteria from when you visited the Estates of the other members. Giving it to Archibald isn't mandatory, but it's the best way to not have him kill you if you didn't do well enough elsewhere.
And no, you can't advance time without advancing the story. Not without cheating, anyway. You can get more Silcrow by looking for Holds, though.