To me it feels a lot like an ordinary jump I would do on foot - on foot I run up to the obstacle, plant my right foot, and jump off it.
On the uni I ride up, drive my right foot down, and then jump off it as it comes up and around on the back side.
(and both feel slightly more awkward using my left foot)
Anyway I think it’s a pretty natural motion, though like all things uni it takes some practice.
Today I wanted to get more comfy with just riding and hopping, so I found a straight stretch and at the end I would stop hop, turn around while hopping and then ride back and then a few times in a row, without putting my feet on the ground. Also after first stopping, I would see how long I could just stand still before needing to make a hop.
I practiced with a 29". On the 19" trials it is easier of course, but I won’t take a trials into the forest.
So far I’ve only been able to consistently make rolling hops with the Hatchet, but that was more than a year ago.
I agree with you completely for your situation, which is being in the lane with traffic. That’s like next-level stuff compared to the above advice, which is for people using the crosswalk. 
There’s the phone thing again! This is why I mostly don’t ride with traffic. 
If I understand you correctly, yes. You want to get in the air with your center of mass in front of the wheel, but when you land, you generally want it to be behind the wheel. If it’s not, you have to get the wheel rolling and accelerate when you land, which is basically harder. The video linked above, while showing really big jumps, also shows the body movements needed to make those jumps; exaggerated as the jumps get bigger. Start by just hopping over marks on the pavement, small holes, etc.
Carry on practicing a bit here and there as you go for a ride. If you really want to improve I would recommend to focus on the smaller wheel first, you will get the hang of it much quicker. Like any other skill on unicycling it is a matter of practicing a lot and never giving up. Don’t get frustrated if you don’t improve much straight away. I see learning tricks and improving skills as a very long term project
I’m well aware that learning on a smaller wheel will go faster, but I always drive around with the 29" already in the car. On my way home from work, I sometimes stop to ride some kms and other times for whatever tricks. The only thing I really have a problem with is hopping on top of something. I know I hop high enough, but I always fear I will trip the moment I do jump onto something.
I’ve already come quite far I think with my hopping skills and I will also try to rolling hop over small pits and markings on the road, like John suggested. It is quite fun to hop I think.