I prefer to let mine free range, too, but will put them on lockdown if I run into a problem or have family coming to visit that will be bringing their dogs.
Weasels are tough - the smaller ones need about an inch or even less to get in the coop. And they are vicious little killers. I think...
A covered secure run will be just fine for your chickens while you're at work as long as it's big enough to prevent them from being over crowded. While most predators typically come at night, you are wise keeping them in the run during the day as most predators are opportunists. I have had...