Yes ecoearth is and excellent substrate.

No. I don't recommend using plants from the garden store. Pathos plants cutting might be ok if you let them grow out and then cut off the new growth, rinse it well, and stick the trimming in the soil. It should take root. This is what I did from a preexisting Pathos plant I had. It is going well even if the trimmings do get dug up all the time.