Re: One small concern
"The weakness with your example is the glass window a few feet away..."
With burglar bars on them. Anyone determined enough to wrench burglar bars out of the studs are willing to just tear the place down and would be better served just ramming through the wall.
"and ease of use is compromised when you lose your keys while out for a walk."
Which is why I keep them in the same place in my pocket every time. And if I lose track, I can retrace my steps. Could also employ a key alarm as an alternative. All else fails, fail safe. Better NO ONE gets in than EVERYONE. You can always call the locksmith or wait for your significant other.