As far as use for dressage goes, I generally advise against anything with too much draft blood. As the workload increases and you begin asking for collection you will break the horse down as they are not built for dressage, they are built to pull carts.
This one is not too heavy but I suspect his movement is quite grounded and from the pictures he looks downhill, out behind and his hocks show very little bending or carrying ability.
He looks cute but keeping him sound in the long run will be difficult. If I were looking at him to lease I would have a full workup done before signing any contract and if he passes that satisfactorily I would start him on Adequan and Legend to attempt to maintain his level of soundness.
They say money doesn't buy happiness -- well happiness doesn't buy horses!