Would you ever..? Im not sure about it..?

Sound like he's been allowed to enjoy his childhood...and that, which is rare for most horses unfortunately. Clydesdale's and other heavier horses do take longer than your average horse to mature so he's had the right thing done by him in regards to being broken at 4 and having light riding if much at all. He has the best chance at remaining sound throughout his life into old age because of this. He would still be farely green I'd say but nothing that some hrs under saddle isnt going fix. If you feel confidant in your ability to handle him then I wouldnt hestitate to buy him. I dont know anything about showing at all so I'm not sure about clipping and braiding rules... but as for keeping his feathers clean a good shampoo and condition will do the trick. You can buy shampoo specifically for white hair to use prior to showing or shampoo with some peroxide added but not much is needed, and rinse it quickly and thoroughly.