i know of a 3yr old warmblood who has had his hooves trimmed maybe twice in his life his hooves are very over grown flared out,chipped,the best i can describe them is they are similar to the size of dinner plates i am wondering the affects this may have had on his soundness..

Well, as you noticed, it results in flares and cracks, and can cause the hoof wall to separate from the inner structures. Long toes also put a lot of strain on the ligaments and tendons which run down the back of the horse's leg, and can cause damage to them as well, if the toes are long enough and left that way. It takes several correct and frequent trimmings to repair the damage caused by neglect by the owner. Grrrrrrr.

When the walls are badly flared they can brush the inside ankle of the other front foot and make a bony growth on it.
Also the flare can seperate the white line where disease can get into there and damage the hoof. The hoof can split at the quarter and if it goes up to the cornory band it could be very difficult to heal and make the horse lame.

I have been a hoof fixer and trimmer for a lot of years!!!

overly long toes can put a serious strain on his knees. it would probably be a good idea to wait on breaking him and riding until a few trims have gotten his feet more under his body, instead of all pancacked out. it may be more of an issue with a warmblood becasue their bones and growth plates mature much slower then hot blooded horses.

This is bad for a domestic horse, not enough running to wear them down. It will affect his soundness, and can make him lame.

a lot
also affect his legs and health

the horse has a very high chance of being lame