Actually the trick is lowering the voltage. A typical incandescent will last practically forever if you drop the voltage to half its rating. So instead of looking white it looks orange white. If you look at the super long life incandescent bulbs they are rated for 135 volts or higher instead of 120 where they are normally operated. I don’t remember the exact relationship but I believe it is something like the voltage to the 12th power (or higher) in the reduction of operating time verses voltage increase. Or in other words, voltage makes a huge difference in operating time.
Yes. That’s why traffic light bulbs last so long. Of course you get less light but your aren’t changing bulbs every few months. Here’s a good article.
These ought to last a while!
Yup. If you could buy incandesent bulbs intended for sale in europe where voltage is something like 220 and use them here (110), you'd have a light bulb that would likely outlive you.