So I've killed off some well equipped Imperials, looted their bodies and want to equip their armor. Does the game take into consideration that I look like an Imperial when I interact with pro-Imperial or anti-Imperial characters going forward?
No one in the game refuses to speak to you based on what you're wearing.
They'll even talk to you if you're freezing your rear off, stark-naked, in front of them. (Though as Communist Duck points out, they do remark on it.)
I have found that the Captain of the Guards in Solitude gets offended if you walk around in Stormcloak armor. Instead of making generic "captain of the guard" comments, if you're wearing the Stormcloak armor, he'll accuse you of being a Stormcloak supporter. If you say to his face, in the Imperial Army's Headquarters, that you hate the Empire, he'll get understandably angry and attack you (though he accepts yields, so clearly he doesn't want to kill you that much...).
So in short, your outfit might add additional dialog options, but as far as I've been able to determine, it never precludes you from any.
This is different from New Vegas, where it did work like that, but remember, that game wasn't made by Bethesda.