The new photos are far better, thanks for posting them.
I will give you my honest critique since you asked... To me he is very far from stallion quality and even as a gelding, may not place well in halter (conformation) classes.
The things which strike me first are:
He has a very plain head. Although if you ask ME the head isn't the first thing to look at, but the majority of minis have at least a short or dishy head which is so desirable. A stallion should have a pleasing head since he's going to be breeding so many mares. If you ONLY are breeding for driving minis and the stallion can knock your socks off in Pleasure classes, then a plain head is more acceptable in my book because "you don't drive the head."
Secondly, he has a very low neck set, it comes low out of his chest. This is very undesirable for both halter and driving horses.
Thirdly, he is not well angulated in the hind legs, which again is undesirable for halter or driving horses.
I don't know if you are looking to breed pretty horses or driving horses, but I suggest that this might not be the stallion to give you either of them.
If you need more detail, I would be happy to lend my eye.
Andrea