I am a full-time community builder in Cambridge, Massachusetts.
I've heard and used "aligned EA" to refer to someone in category 2 (that is, someone deeply committed to overarching EA principles).
I don't think arrangement 1 (investor buys house and rents out just to EAs) is better than arrangement 2 (investor invests in whatever has highest returns, and EAs rent most convenient house) since the coordination required and inflexibility might be too much of a downside.
If the goal is to reduce costs of living together for EAs, the investor could subsidize the rent for the group of EAs while investing in something completely different with higher returns.
Some possible benefits of arrangement 1 are if the cohabitating EAs could actively make the house a better investment through e.g. maintenance. In other words, they would have a stake in the investment making good returns, and so would treat the house differently than average tenants.
Some thoughts I have:
Quantum randomness seems aleatory, so anything that depends on that to a large extent (everything depends on that to some extent) would probably also fit the term.
Winter solstice / summer solstice? Popular secular holiday in EA circles (though not strictly EA per se)
In case someone has capacity to do this right now, I'm under the impression that Open Phil does want their own page (based on conversation I had with someone researching there).