There's not much to say about Gordo except that he's the result of a person who's just been beaten down so long that he just doesn't care anymore. He has nothing but contempt for King Dedede and barely does anything he says. In fact, he takes pleasure in seeing him fail. Unfortunately for him, Gordo has been appointed as a confidant for Dedede, by Dedede, which means he has to listen to him give all his villain speeches or workshop all his hairbrained, guaranteed-to-fail schemes. Dedede puts a lot of stock into Gordo because he is invincible (by and large, but not absolutely), and thinks Gordo is worth having around just because he's a "solid guy". For that reason, Gordo will probably never be able to leave Castle Dedede, and he hates it. No matter how hard he calls out Dedede, directly berates him in his face, and otherwise tries to get fired, it usually just doesn't happen (though it may have in a comic or two).
Gordo's opinion of Kirby is similar to Waddle Doo. If ever sent on the field, Gordo will let Kirby know Dedede sent him, and then won't take any action against Kirby. The difference is, Gordo doesn't hang out with Kirby. Not only that, but Gordo doesn't even care if Dedede sees or knows about his refusing to comply with the king's orders. What's he going to do? Take a hammer to his head? Gordo knows that that will just destroy another one of Dedede's expensive hammers, and the only one who loses in this situation is the fat bird himself.