As for bikes being more advanced - yeah, sure. Bikes are examples of really mature technology. While there's certainly been improvements, for a casual rider none of them have much of a wow-factor.

"shifting only in one direction" certainly sounds like the shifter cable is gunked up, with the return spring in the derailer not being strong enough to overcome the resistance. Easy enough to fix, even for a rookie. Several good web tutorials available. Parts are dirt cheap too. Even handing it over to (another) lbs shouldn't upset your economy too much.
As for saddles - don't expect too much. There's a reason why you don't find bike saddles used as sitting furniture anywhere else.
It's a bit like a pair of traditional leather boots. It might fit you just fine when you're in the swing of it, but leave it off for a while and it'll chafe at first.