1. What is the difficulty on the mechanics check?

2. Is the damage just what is shown?

It's a touch old, but there's some good ideas in this thread:

The way I'm planning on running them in my next campaign, is they roll to hide the mine (stealth or survival in most cases) difficulty determined by the environment, then that will determine the difficulty for enemies to spot the mine. Then if they set it up as a pressure mine, I would say the mechanics check would be easy, haven't decided if it would be upgraded. If it's set up for remote detonation then it would be average with an upgrade, and setback dice equal to the number of range bands they are away (1 for short, 2 for medium, 3 for long, etc). Then adjust how it works as needed

That's how I'm planning on running them, hope this helps.

I had an issue with this as one of my players was trying to use mines in personal combat almost like grenades. When this is done it is hard to take the RAW approach because it doesn't make much sense. I like Imperial Stormtrooper's approach. Stealth to hide it, some other check to spot it.