I can understand your obvious frustration. I also think that it is good that you vocalized it here. Just to let you know, we all have been there (trite, but true) and part of the process is learning that it is okay to ask your partner to lighten up, or not grip as hard, or to go with the technique. Its also okay to ask them to resist and try to get up when pinned, etc...
I would suggest saying something like "I have no idea how to do this yet, can you help me by moving your body in the direction that you remember the instructor doing it to you" and get the instructor over to show you how to do it so he can feel it. You will probably want to take uke as well to feel it and work with that.
On the other hand, the "You know when you grab my wrist so tight .. that stuff doesnt work with me , because i'm stronger than you" would be infuriating and I can see wanting to drop him crying to the mat. In my opinion the better way is to keep your cool and whenever he throws you get up effortlessly and without a hint of noticing that he had thrown you. Also a little bit childish, but there you go...another way of making the point.
Really...better just to agree with him and then get back to the technique. <wry grin>
Which brings up the "nage getting all the blame" point...everything that happens to uke happens because of something shite (or nage, if you will) does. If they push when they are supposed to pull...or pull when they are supposed to push or don't do anything at all shite still has to work with what is given to do the technique. I will often tell uke to move with it for a couple of times to help shite out to see what is supposed to happen, but there is no way you can say that uke "did something wrong". Shite's role is to deal with uke and put them where they are supposed to be. End of story. Finished. That's it. It's one of the reasons we train with multiple partners...so we can learn how to move various people.
If this guy bugs you I recognize that it might be counter-productive to train with him. On the other hand, if you can use it as an opportunity it just might make your Aikido better. It certainly won't be as much fun as training with someone you respect...but if you can get something out of every time you move on the mat and with anyone you train with then your Aikido will improve everytime you are on the mat. And that is a good thing...Something else to think about
Just my few yen,