Is there a way to remove the switch users Icon without root? I have a Verzon Moto E2 (so no hope of rooting) on android 5.1.

I think you cannot completely disable it without root.

I'd like to at least remove the little icon in the pull down menu. is that possible using ADB without root?

Thanks in advance!
Unfortunately is impossible without root.

You can however Root and if you have any problem that need go to fix it, you can Unroot the phone.