Problems after suspension rebuild

What alignment specs were used? Was any driveline work done at the same time?

The vibration is unlikely to be the suspension components, much more likely that it’s a wheel, tire, bearing, or driveline issue.

The creaking could definitely be a bushing. If the suspension was tightened while hanging instead of at ride you may have torn a lower control arm bushing. If the bushing is already torn then loosening and re-tightening at ride height won’t change anything. And if the creaking is a bushing, it’s most likely already torn. But even in that case, the bushing is unlikely to cause a steady speed vibration. The steering or handling might feel wonky, the creaking would make sense, etc. But a vibration at a constant highway speed is unlikely.