Hmm. All of those measurements are well within the range of "normal".

Any broken threads/cords inside the tire?

What tools do you use to install the tires? (sounds like a box knife is involved -- just kidding)

Have you tried talc powder outside the tube?

After installing, do you inflate the tube to ~20psi, then empty, then pump to full pressure?

Have you tried mixing and matching with other tires or rims?