About the fees, I haven't used Mycelium for a while, but I'm pretty sure they allow you to customize your fees starting with 1 sat.
I do have Mycelium installed, but I use it watch-only, didn't actually make transactions with it.
However, the fees are not written as numbers, or at least I didn't find such a setting. The setting I've found allows you select between Low-Prio, Economic, Normal and Priority.
https://i.imgur.com/mv5ALOx.pngReally? I remember seeing a custom fee slide that went through almost every fee possible (from 1 to ~400), but I dont have an Android anymore to double chrck.
Thats how it looked like:

Isnt this available when youre in the Sending screen?