At least in Finland the 30 minutes is meant to be 30 minutes sitting down and eating your food. If your place of work has a shared cafeteria people are meant to eat lunch in, getting from your desk to the cafeteria and back, and queueing for your food aren't meant to be part of the lunch break. Only the part you actually spend eating and thus properly on a break.
It's a bit of a spirit of the law thing, though the law is quite exact on the matter. Good luck trying to find an employer outside desk jobs who actually abide by it, though, as factory jobs are scheduled around 20 or 30 minute breaks and if you're not back at your line by then, production halts. Luckily that fact is typically compensated in the pay.
I'd assume other European countries with 30 minute lunch have a similar clause.
Yes, performance fees were, and still are a thing. That's why there are separate streaming services for playing background music in e.g. restaurants and malls, which have licences that cover that use case. You can't just use e.g. Spotify even if you pay the appropriate fees separately, at least where I'm from (Finland). Same goes for playing TV and radio in the background – if it's specifically as background noise or e.g. TV at a bar you typically need separate licencing on top of the one used by the channel itself for distribution. Might be different in the US for example, but copyright laws tend to be quite similar across countries (unfortunately).
The smooth jazz in malls part is likely a lot due to the (historically) overwhelming market share of the company Muzak. They were the pioneer of background music in commercial environments and got a strong enough presence in the market that their name ended up a generic one. AFAIK they're still a large player in the business.
Mall music basically ended up as its own genre due to Muzak and how big it became, and started influencing other media as well. As an example, the style was referred to in the soundtrack of the first Sims game in the buy mode, where it brought with it the feeling of rampant consumerism and buzz of purchasing new stuff. At least according to this video essay on the subject, which in my mind makes its point quite convincingly. (~~the relevant part from 11:46 onwards~~ re-watched the video and the relevant part actually starts at approx the 5 minute mark, but the video is altogether quite interesting)