1 - I don't know. Not programmed that way I would guess. It's a measure of popularity rather than recommendation from individuals.
2 - It's tough to say for sure, people who know the equipment better would have a more informed opinion. Distance can be a subtle thing with routers. I can get signal 250 feet away from neighbors, I think both router and cable router. But outside my public library, which has brick/block walls with triple glazed windows, I can't sit in my car 55 feet away and get signal. I have to be 20 feet outside the front door.
And they would need your password and software setup to connect with your router and wifi. Now if they were good hackers they would know how to do this. Supposedly back in the day, although it was technically illegal,, people could use a "cantenna" to concentrate wifi signal and somehow login or around it. I don't think that's done very much anymore. Cantenna was a tin can or funnel pointed here or there to find signal strength. I guess they had wires that fed into the modem port.