For example, can I use a .house domain for a website that has nothing to do with real estate, homes, or construction?<p>What kind of authority does domain registry companies like Donuts Inc. have? Are they able to seize domains as they wish?
For sponsored TLDs, it's up to the sponsoring entity on how to establish and enforce rules <a href="https://en.wikipedia.org/wiki/Sponsored_top-level_domain" rel="nofollow">https://en.wikipedia.org/wiki/Sponsored_top-level_domain</a><p>They probably have a TOS you can read on their main page. You mentioned the .house TLD, and according to name.com (which is one of the places you can register that TLD) "There are no restrictions on .HOUSE domain names. Anyone can register for any purpose"<p><a href="https://www.name.com/domains/house" rel="nofollow">https://www.name.com/domains/house</a>
Unless your name is Dr Gregory House, why would you want a domain in a TLD that is unrelated to what you doing or selling? I would guess that search engines as well as potential customers are going to be confused by such a decision.