Mojeek has answered the question about open sourcing their engine here https://community.mojeek.com/t/is-mojeek-open-source/237/2
They are constantly tweaking so it will get better.
There are many search engines out there now. A lot of them are just Bing, but a few like https://www.mojeek.com/ have there own index.
https://www.searchenginemap.com/ is a good place to look for more info when you want to get away from Google.
What’s this about weak security? Do you have something to read about that?