Do I need new fasteners to install this?

The arm bolts to factory mounting points, but hardware is not included. You'll need the OEM bolts and castle nuts from your truck — most shops reuse them unless they're stripped or damaged.

Will this fix my steering wander and wandering at highway speeds?

If your wander is caused by a worn upper control arm, yes — a worn ball joint creates slack that destabilizes steering feel and alignment. Replace it and your steering will tighten back up.

Can I install this myself, or do I need an alignment after?

Installation is straightforward for DIY — you'll need a press to swap the ball joint if your old arm's is serviceable, or the new arm comes with one already installed. Get a wheel alignment done after install to dial in your caster and camber.