Whenever I'm in someone else's house and they have an interesting bathroom scale I try it out. Based on that, I believe my home scale ( ca: 1975) weighs 2-3 pounds light.

I rarely weigh myself and only do so in large intervals so I can look at a long term trend rather than short term fluctuations. I have weighed nearly the same weight for a year but have got substantially leaner...so I take weight with a grain of salt since I do resistance training. I prefer using unforgiving clothing like jeans and taping myself as a guide instead. I don't care how much I weigh. I care about how I look instead. I just fit into a pair of Jean shorts that have zero stretch that I haven't been able to wear probably since my military days. That's good enough for me.

Almost never. I'm after improvements in appearance, muscle growth and fat loss. Stepping on a scale tells me none of that. When you step on a scale the only thing you learn is the effect gravity is having on your body. I look in a mirror, take measurements or get a quality body composition test.

Interesting. I've always heard it wasn't a good idea to weigh too frequently. A good strategy is to weigh yourself say, once a month. But to rely on how your clothes fit. Pull out stuff you've not been able to fit in for a long while. It's fun and confidence-boosting.

I weigh myself every day. I'm trying to solve the problem of why the body fluctuates in weight throughout the day through dietary and habit adjustments.