I would offer use of the facilities the next time he's here. Once here, I don't require them to knock each and every time, just tell them to please come in, the bathroom is over there, and help yourself to water/ice if you need to (usually they have drinks, though). If they're going to be here all day, I would expect they may need to use the facilities at some point. All kinds of creatures pee in the wild, and for me, I just think I wouldn't worry about this one. It's temporary.
If he works for a business, you might call and ask what the expectations are for the workers. This guy sounds disagreeable enough, I wonder of finding someone else might be a better choice. As CrazyDaffodilLady pointed out, you feel like you're over a barrel sometimes and you don't want to antagonize them, and you haven't exactly started out on the best footing. I don't think I would say anything about him urinating in the yard at this point, just make sure he can use your bathroom when he needs to. Also, I hate to say this, but if you have a male around (I'm assuming you're female) to help field the work to be done, this might be helpful with some of the other issues with the install.