I've got a lemur, running 10.10, and I'm having issues figuring out how to configure my wifi.

1) When I boot up, wifi is always disabled. Optimally, I'd like it to keep the state it had at shutdown, or if that's not possible, I'd like it to default to on.

2) When the computer is on battery power and the lid is shut, wifi turns off. This means that if the power blinks when I'm remoted into the machine, I'm knocked off until I can physically get in front of it and re-enable wifi. I'd like it to only turn off if it goes below a certain battery level. I'd also like it to pop up a message with a timer and a cancel, so if I'm remoted in, I have warning and some control.

3) One of my wifi networks does not broadcast a SSID. My mobile devices handle it just fine - once they've been introduced, they'll join without any action on my part. But this machine has to be re-introduced every time. How can I make it join without prompting?