Gee guys, aren't you worried that someone will rake you over the coals for asking questions about Reace's choice of chassis components?
I suppose it's okay if you don't mention shocks :
Yes, the stated reason was the ease of changing ride height to suit different truck box heights.
Yes, some load sharing between multiple axles helps ride, and a Torflex system doesn't do that.
Also, all suspensions have springs. The design used on the TA uses leaf
springs. I have no explanation of why some people use "spring axle" to mean "leaf spring suspension".