My ambivalent reaction to this post motivates me to make a distinction between two kinds of advice; I will call the first "community-normative" advice and the second "agent-pragmatic" advice.

On one reading of your post (as community-normative advice), you're basically telling people in general to do what the title says: "Don't get offended!" My gut reaction to that is along the lines of handoflixue's comment, only with less profanity. Everything anybody ever says is a speech act, and some speech acts are harmful, and some are intentionally harmful. So telling someone not to get offended is kind of like telling them to stop getting in the way of moving fists. Potentially a sign of moral myopia.

On another reading of your post (as agent-pragmatic), I see sensible advice for any individual thinker in the abstract. Yes, if it's possible to cultivate a general disposition not to be offended, that might be a good idea, in the same way as cultivating an immunity to arsenic might be a good idea if you live in an Agatha Christie novel.

I think the difference between the two is that if you say "Don't get offended!" without disclaiming the community-normative implications, you're imputing blameworthiness to those who are (perhaps maliciously) offended.

To be fair, you did actually disavow those implications.