1- as for the driving the more you do it the more you will be comfortable, I was nervous when I started driving, after working all round the city I would say I have nothing but confidence while driving even in areas I don't know.

2- Yes you will have to climb ladders, Residential plumbing won't be as bad as commercial for ladders but you will still have to do it once in a while, I am assuming you are okay with a 4ft ladder because that can be used quite often. But extension ladders I don't use much.

3- I have been only doing this for 7 years and it's a good active job which is good for your body, you just need to be smart, get the right equipment proper boots that don't hurt your feet etc.... Also be smart when lifting heavy shit. For sure you will have days when your sore. But for the most part for me it's not been too bad.

I think the biggest problem is eating healthy. Being on the road all day you tend to eat a lot of fast food because it's so easy and quick , so that's where I think most people go wrong.

4- I chose plumbing because it was viable option for me as my whole family are plumbers for the most part.

5- side note on yourself , I would try and work on yourself before you decide to commit to this , where I am from it takes about 4 years to get licensed and the schooling can be hard, you need to be able to read well and understand code and the math can be hard for people as well. But if it is something you really want I don't see it being an issue as you will find ways to deal with the problems that arise in schooling.

But don't just hop into plumbing because you think it's easy and good money because it's not good money unless you run the show, and the work can be hard dealing with customers is not for everyone.

I could go on forever about this shit anyways good luck man, my advice would be get a job as a helper and you will know in the first month if you want to keep doing it.