Good questions but typically watershed ponds get too warm for trout at lower elevations so I can't answer your question on how it would effect you at your altitude.
Keep in mind there is less oxygen saturation at higher elevations. It may not be an issue though.
Are the trout that are local also in ponds?
Also keep in mind that a bubbler/circulator can work against you if the water temps are marginal in the hottest part of the summer.
OTOH i used to shut my diffuser off during the day in my trout pond due to the fear it would warm the water too much. Turns out those fears were unfounded. This only brought up temps a couple of degrees and even then temps in the entire column stayed at a uniform 62 F. max in the hottest part of the summer.
However my pond is small, has, steep banks, and a small surface area in ratio with the depth. One could have issues with a pond with a larger surface area and less slope as too warm of water.
Make sure your banks as steep as possible to reduce warming. It will also reduce nuisance aquatic plants.
