Antonin finds Barty annoying, NGL. Probably because he's a bit anti-hard work. :P But, he IS loyal and will respect that about Barty. Just not sure he'll enjoy dealing with him for any extended amount of time, lol. XD
James would have gone to school with Barty for some time but I think he might have left Hogwarts just before Barty hooked up with the Slytherins so he probably never formed much of an opinion about him. Likely thinks he's just another pureblood living off his father's money. This opinion is bound to change soon enough. :P