Honestly, a neuter is no big deal. It doesn't hurt nearly as much as a spay because your not going into the abdominal cavity.
It really is the best thing for him. Behavior wise it will stop marking, humping, and aggression (sometimes they will still mark). It can also prevent future cancers and problems. Unneutered males have a higher chance of having prostate problems, including prostate cancer. They can also get testicular cancer. Urinary tract problems can also arise. Perineal hernias are a big problem too.
I work for a veterinary surgeon and see these types of problems all the time. They are usually in older intact dogs and its so much harder for them to recover. So yeah, your intact male may be healthy for maybe 3/4 of his life, but do you want the last 1/4 to be filled with suffering you could have prevented if you just neutered him.
if he's going to be under for his teeth to be pulled, just get him neutered at the same time. you both will be much happier
here's a site i just found while googling 'reasons to neuter'
Reasons For Considering Neutering or Spaying Your Dog or Cat | Ask Vet Advice