Yes. Use the threadlock on the hard drive screws. Don't tighten the screws too tight and let the threadlock provide the resistance.

And around here the blue threadlock is in a red bottle. Just read the package and make sure it says something about it being easy to break with hand tools.

The washers are just to make up for slight irregularities in the flatness of the drive and the tray. Having the drive stand off any is enough.