Welcome to permies Joe
As Jennifer says, canes are pretty tough.
But in my experience thornless blackberries
really resent their roots drying out or being in the light.
I can't imagine wild blackberries care at all though!
I'd just poke the canes into buckets (or something) and cover the roots with moist
compost (or something)
As for pruning as you plant, I'd leave them. That sounds like a fine height to me.
I don't know your climate (you can add it in 'my profile' if you like)
but I'd probably avoid pruning anything until very early spring.
Offtopic, but I love growing canes so here's a few hints:
when my blackberry's new canes get say, four feet long, I cut off the tips just above a set of leaves.
This makes the cane send out lots of fruiting side-shoots, rather than stretching out in one direction.
Also, if they're a variety which needs wires/trellis, make sure it's in place before the canes start growing as they can grow really, really big in a season.
Oh, and don't be shy about pruning-they like a major seasonal haircut; just make sure you only take out old canes that have fruited