>>what is your opinion of unions who fight for exemptions from the very political/economic causes (minimum wage, ACA, etc.) they claim to align with politically???

Do you think the US tipping culture has an effect on wages and expectations?

For clarity: apart from 1% enclaves, in most of the First World there's no expectation of a tip for your bar person or server. Or anybody else for that matter. In a restaurant you pay the price on the menu that also usually includes sales tax, and that's it. Sometimes you choose to tip a particularly good server, but that's entirely discretionary. Obviously it's society's expectation that employers pay everybody a living wage.

The US examples given in your citations are large hotel and restaurant workers. What sort of tips should they expect in the USA and do you think it might be possible to accept lower wages in exchange for other benefits?

Not making any sort of statement, just thinking about the effect of tips on income and wondering whether some workers might prefer to work almost for free because their effervescent personalities generate a fortune in gratuities.