However I get a few dropouts - maybe 1 or 2 a day.
Q1: Why? What causes dropouts? How can I avoid them?
In order to crack a WPA encrypted wireless network, one needs to bump a connected computer off the network, Windows will automatically reconnect when the connection is lost, this is where the hacker collects the only packets that will have the key, which is the four way handshake before a connection is established.
It might be a good thing your OS does not automatically connect, if the hacker is impatient, he/she will give up within a minute and try something different later to try and get those packets from the four way handshake.