First paragraph - It's derangement to pretend that there aren't a host of reasons people (including me) may support a wall. As noted, I'm not tied to the wall, but I certainly don't think that if I conclude it's a wise choice, that choice is by nature racist/disparaging/etc. I can agree with most of your recapping of how Trump incited prejudice during the campaign, and that that type of rhetoric played a key role in his popularity, however.
The need to impute that on everyone who supports a policy supported by Trump, however, is mindless.
Second - No comment or disagreement, but I'm not sure of the relevance.
Third - I don't blame you for looking to the intent behind the wall that Trump and/or Trump supporters may have and letting that impact your position on the policy. I do that as well, and it's colored my thoughts on the wall, actually.
My comments on the "hive" do not relate to the idea of Trump's degradation of Mexicans. Is there some kernel of truth in Trump's comments? Yes, of course. Are his comments boorish, overbroad, and intended to incite prejudice and motivate the lowest common denominator to become passionate about a policy objective? Yes.
Rather, my comments relate to the inability of those who oppose Trump for who he is or what he says to distinguish between Trump, Trump's most nefariously-minded supporters and those who support Trump or Trump's policies as a means to a desired end. Some would probably respond by expressing their opinion that Trump is so awful that supporting him or anything he wants to do for any reason is simply unacceptable. And with regard to people of that sort, any constructive discussion is impossible.