Yes, you can introduce ich to your tank via corals, snails, etc. Ich can rest/live on any hard surface that has seen the parasite in the last 8 or less weeks. Do you have a quarantine set up? I QT corals, live rock, etc to avoid any possible introduction of ich into my DT.
At the very least, dip your corals in something like ReVive.
Stick with very hardy corals if your tank is always in that temperature range. Try mushrooms, zoanthids, paly's, button polyps, etc.