We have our own index, its not a shitshow of mixed results like Searx tends to be. this also means that we're not chasing breaking changes of some larger engine when they decide they dont want us, like Twitter did to Nitter, and Bing did to Searx.
We don't know how to monetize. Ads are the only option that we know of, donations do not work at all, as proven by my previous projects.
We've already got spam prevention and removal measures in place, but I won't discuss them.
We don't know how to scale it since its centralized by design and the frontend and backend are tightly integrated, largely because the frontend is largely generated on the fly by the backend. Maybe host a copy for each region we're aiming to acquire users from?
Our engine already understands 5 languages, and we hope to expand to CJK languages soon.