If a child fights diapers, it is a sign he is time for a change. Start pottying him and see where it goes from there. I'm not going to continue to fight with my child if he is trying to tell me something, especially that he is tired of diapers. (They can get uncomfortable, very uncomfortable. I wear them twenty-four seven for incontinence reasons, and I can truly and fully understand how a bay woudl feel. If i could, I"d get rid of diapers and never ever look back.) Put some training pants on him, get him to the toilet on a set schedule, and your life will be much easier. I learned this from my best friend's mother.
My very best friend was completely potty trained at 14 months old. It only took him around two days. He began fighting diaper changes with all is might, and yes he did fight to the point of biting, kicking, hitting, and even running off during the change and hiding, and his mother listened to what he was trying to express. She sat him on the potty, and it went from there. She got a schedule with pooping and peeing, and he was through it very quickly. He is extremely intelligent and has always been ahead. This could be the case with your son. Give it a try and see where it leads.
As for the clothing thing, what kinds of materials are you using. Perhaps, he is telling you, or at least trying to, that he is not feeling certin types of fabrics. i know for me that I've always prefered certain types of clothes over others. I've been this way since very early childhood. I hate wool. It irritates so much that it hurts. I used to scream and scream until someone took it off me if it was put on me. I also hate stockings material. I don't like lace, mesh, or silk. I do prefer jean material, cotton, flannel, satin--not the same as silk, and starchy things. Try different types of materials and see if the reason he is fighting you is because he does not prefer certain things over another. Whe our children cannot talk, it can be frustrating, but if we are diligent and attentive, we will understand what they are telling us, which will cut frustrations down to a minimum. It will continue until we figure out what our kids are trying to say.
I hope this helps you out.