My take is that "the line" migrates as you A:advance in your career, B:as your tenure with the company elongates, and C:as both your value in the marketplace and your perceived value to the company change over time. The type of response that your career could survive depends on these factors. Businesses nowadays have embraced "doing more with less" as a pseudo religion, and people need to sound off when their level of "reward" isn't consistent with the demands of their job - or merely swallow all of it and resign themselves to being used and unhappy. By "reward" I mean the total benefit (money, satisfaction, prestige, comfort, perks, etc). Everybody has their own formula of valuation for this stuff, and everyone needs to use it to determine where "the line" can/should be drawn.
Yes and no. If it is demeaning or unreasonable or I'm not qualified, I'd stand my ground. Sometimes, I'll go along to get along.
This is one time when Unions can be helpful.
do not take sides or be unethical. I gotta cruise to go to hospital. sorrry. I hope you can be kind. try to be nice.