Welcome to the ACA Forums!
There are several things that need to be addressed. First, the saddle. Saddles are EXTREMELY personal. Use only what works for you. That said, a lot of cyclists that spend a lot of time in the saddle actually ride saddles with no padding. Others do but they are definitely not the "tractor seat" type of saddle.
I personally use a leather seat on all my bikes since, once broken in after 500-1000 miles, the saddle fits your personal anatomy so it fits like a glove and supports you quite well. Others prefer the better quality saddles with some padding as it provides a little cushion on the seat bones. These riders typically, but definitely not always, ride more casually such as on the weekends only for up to 50 miles. But let me repeat that use the saddle that works for you but do not be afraid to try ones you "think" you might hate. A lot of bike shop and/or saddle manufacturers have a fairly generous exchange (not refund) policy so you keep trying saddles until you find one you like.
As far as shorts go, you do not need to purchase a padded short though they do help. For a better fitting one, maybe try Terry brand. Though they are geared for women, someone who is XS may benefit from them. They too have a decent return policy.
The big advantage of biking shorts is not the pad but the liner (or chamios) basically reduces the friction between your skin and the short. It does this by somewhat clinging to your skin and then slides on the short. This greatly reduces skin sores which will eventually become infected, irritated, and painful. In the old day, shorts did not have pads, only the chamois. BTW, the reason cyclists do not wear underwear with bike shorts is because the underwear seam can rub, causing irritation.
Once you find a pair of shorts that you like, you might consider buying several pairs as the manufactures tend to replace them with "improved" models that may not always feel better to you. That said, like saddles, if you prefer to ride in a non-padded short, then go for it. Just be sure the short slides on the saddle and not against your skin or you will get skin abrasions.
Finally, you do NOT need to be able to ride up to 100 miles a day before touring. I would suggest you be able to comfortably be able to ride 50 miles in a day though. But then again, you really do not need to be able to ride much just so long as you plan your days accordingly.
Tailwinds, John