Yeah, most hotels I've been in used electronic locks with no moving parts you can hook that to. Just a card reader on the hallway and a door knob inside. Door knob works as the additional lock (upward position in a European style knob) most often.

I would still use a door stop - a rubber one doesn't weight much. But I would just carry one - with my luck the other door would be a slide door or open outside.

It looks to me like this device is preventing the deadbolt knob from turning, not the doorknob. It's only using the door knob shaft for support.

Yeah, globe shaped doorknobs are on their way out in general because they’re less accessible for people with disabilities/weak grip.

Globes are better for keeping intelligent cars/dogs/children where you want them though.