Airship design has advanced since the Hindenburg. Notably, they don't use hydrogen anymore.

It's not a problem of reflectivity, it's a problem of resolution. In order to detect something distinctly from other things (i.e. resolve that thing), you must be able to distinguish its reflected energy from that of other things by separating them along one or more dimension. Range is usually a good discriminator, but there are many things at (nearly) equal range to the radar. Azimuth is typically not great, because azimuth resolution requires a physically wide aperture, and real estate on the bumper is expensive. Doppler is great for moving things because it's easy to design a waveform with a small doppler resolution, and most moving things (cars, bikes, people) don't move at exactly the same speed as other moving things. However, nonmoving things have a very consistent velocity of precisely 0, and there are lots of them. So they can be very hard to resolve, and thus to detect.

In practice, the difference between pulsed radar and continuous wave radar is a continuum rather than a dichotomy. Historically, FMCW (frequency modulated continuous wave) had a high duty cycle (though not 100%, the ramp generators need finite time to reset (though you can alternate between up and downramps and get closer)). For some applications, though, requirements force you to short ramps and long PRIs, thus low duty cycles, but the name (FMCW) sticks.

This is true for some earlier lofi radars, but as driver assistance and self-driving have developed, so have the requirements and capabilities of the radar systems. Newer systems generally have shorter PRIs for higher doppler bandwidth, and much higher duty cycles for more energy on target - the FCC limits power, so you've got to get energy from the time axis. Both of these things make the interference problem harder.

I agree that you can't know what is "real" without looking at our universe from outside it, but that, in and of itself, doesn't imply that every model must be flawed, in the sense that its predictions must not be 100% consistent with observation. We could stumble across the "real" model, or something equivalent to it (in the sense of identical predictions) - we'd have no way of knowing whether the model is "real", but it could still be right.

I find laying of blame to be the most egregious waste of time, for work as well as personal issues. People who insist on it are, by and large, not people you want to spend time or money with.

I was confused by that terminology at first, too, but it appears their product has an "offer" phase where the meeting organizer suggests multiple times, and a "book" phase in which the invitees accept the meeting and it's booked. Which doesn't necessarily mean that the meeting is attended, but it is a higher level of confirmation/buy-in from the invitees than what happens at my work (FANG) where organizers just throw meetings on everyone's calendar.