I would geld, there are a lot of mini's on the market and if you don't know his breeding it is probably not worth it. He his cute, and I like his color. His head is rather large and coarse, his legs are short while his body looks really large. How tall is he? Is he a registered miniature horse? You said he is skittish is that improving? I just don't think its a good idea to bred a horse that is showing a skiddish personality without improvement. Is he a cryptorchid? It can be fairly common in the breed (from my limited experience) to have horses with retained testicles.