The SFE should not bother any of your fish. They do however like inverts.
As far as the stocking level for a 72 IMO it's a little overcrowded. I would leave it as is, and keep in mind that the sailfin will outgrow the tank. I think if you removed the SFE, and sailfin, then you could consider adding a couple of smaller fish. Keep in mind that mandarins do require lots of LR, and a well established pod population.
The 40 gallon I would consider as complete. Sounds like a good mix of fish, and I would leave it at that.