all of the above!
potty targets are great for little fellows (and big fellows have a sneaking appreciation for 'em too.) you can buy them but why? just find something that floats and have him aim. he needs to direct his flow himself. sometimes an untethered nozzle will spray off in odd directions. teach him how to be the master of his own ship.
and it's great that you've got him cleaning up. don't stop just because he's not good at it! he's only 5 and probably not great at cleaning anything yet, but you're rockin' it by having him give it his best. supervise it gently, encourage his efforts, and go back afterwards and mop up anything he didn't get. this too shall pass. (sort of- any time you live with men there's splash fallout.)
going outside from time to time is fine, but you're right, you don't want it to be the default. when my kids lived here i begged them to pee around the outside of the flower beds to discourage the deer, but noooooooo, they didn't want to help a mom out. now that they're grown i find 'em peeing off the patio at all hours! cretins. i suspect it's because they live in the city and enjoy the privacy of being able to pee outside here at the farm.
:) khairete
S.