Tenet 3(a) is not much more than a statement of ecological maturity that we take care of our home world because it takes care of us; that we obviously should not put poison the area from which we eat and drink; that we need to keep the ecosystem safe and sound for all species; and that we recognize the existence of toxins and ideas contrary to and opposed to that social harmony, such as disease, the corruption of power, and warmongering.
Tenet 3(b) recognizes the great distances to other stars with habitable planets orbiting them. Look at the stellar distances of about the 50 nearest stars, which cover an area from 4.2 to 16.3 light years distance from earth.
Light travels about 670,618,800 miles per hour (186,283 x 60 x 60) . Voyager 2 travels about 38,000 miles per hour.
Light travels about 5,878,644,400,800 miles in a year (670,618,800 x 24 x 365.25). Voyager 2 travels about 333,108,000 miles in a year (38,000 x 24 x 365.25).
Thus for each year that light travels, Voyager 2 must travel 17,647.86 years (5,878,644,400,800 / 333,108,000) to match that distance.
If the nearest star is 4.2 light years distance, Voyager 2 must travel 74,121 years to get there (17,647.86 x 4.2).
Voyager 2 is the longest lasting of our current spacecraft, and it is only about 32 years old in terms of space travel. Would it last 74,000 more years? And what about the return trip?
Tenet 3(c) recognizes that we won't find a habitable planet unless we look for it, which the Kepler Mission is trying to do.
Tenet 3(d) is the next logical step, colonizing a habitable planet after finding it and travelling to it.
Tenet 3(e) recognizes that stars will all die out, so this process of finding, going to, and then colonizing planets orbiting stars must continue as long as we are the human species.
Tenet 3(f) recognizes alternatives to the process in 3(a) - (e), such as the realm of the mystical and the realm of the religious that believe divine beings or some mystery force will help us become a different type of being no longer needing stars and planets in order to survive; and Tenet 3(f) further recognizes the ideology of further evolution into such beings without divine or mystical intervention.
In short, whatever works in order to pass The Test, is fine with the Tenets of Ecocosmology.