Being able to move them, however slightly, can be really useful: either for slight repositioning if you've made a mistake in placement (e.g. covered some offensive turrets), or more devious tactics.
And I'm not sure being able to rebuild them is something that needs a nerf to compensate for... does rebuilding actually save any money? My understanding (probably faulty) is that rebuilding costs half the turret cost, and once rebuilt the turrets are at half HP, and that repair in general costs the full amount... which is the part I'm actually doubting...