My Extended Test Drive... Need help!

Typo fixed.

 

As to the seat, leather ain't gonna help, so save your money.
First off, did you read your manual with regard to the seat adjustments? Did you try playing with the seat height adjustment? I found that quite helpful to try different seat heights in order to find the right one.
Secondly, lumbar pillows and other seat cushions are available at well under $50. Check at Walmart, Target, Pep Boys, etc., as well as at your Toyota dealership parts dept..

As to the steering wheel, there is no help for the wheel positioning. You will just have to find the position that suits you best.
One more thing I found that really helped was a slip-on steering wheel cover that had some padding. This allowed an easier grip on the wheel. - otherwise the steering wheel felt like a thin twig, covered with sandpaper.

After driving my Prius for 20,000 miles, I must admit that I still have misgivings, and often feel that I should have given up some of the mileage for a greater degree of comfort [The Japanese still do not make many of their cars to fit European-size human beings.]
... but the mileage is GREAT!

 

In regards to the seat and arm comfort while driving.....

Is this something that would impact your daily driving, or more for extended driving? In other words, if you work and your daily commute is 15 - 20 minutes, would the seats and arm rests be an issue?

In other words, if the complaints you had were for 1 - 5% of your driving experience/time and the car is comfortable for the remainder, you can work around the times when the car is lacking in comfort.

I don't care for where the arm rest is on the door (too low), I think I get around it by not having my hands at "10 and 2" and instead using the hand holds in the lower steering wheel. I don't always keep them them (I try to do 10 and 2) but will revert if my shoulders start to hurt and/or I need to rest my arms.