Realize how you can reduce your fears to nothing.
>1. Fear of not having thought of ever legal angle.
You pay your lawyer to figure that out. If you get a C&D figure out then what your solution is, don't pre-optimize.
>2. Fear of no one using my website. And then someone else coming along and beating me in this area and making me look stupid and like Friendster.
Then you just have to advertise. Or, you'll realize you designed this in a bubble and you never had any users to begin with. At that point you've learned something.
> 3. Fear of the product not being polished enough.
Or it's so shiny right now that the glare is pretty bad. That's why it's called a minimum viable product. If you put another 100 hours into polish, why does that even matter if you end up iterating and tossing the existing UI. Or you could have used those 100 hours to make the awesome new feature that all your users are clamoring for.
> 4. Fear of rejection from lots of people at first look which leads to people never coming back to the site.
A/B testing. You didn't design this in a bubble, right? There's obviously some value that you're looking for. And if those people bounce, don't spend too much effort because they're not your target customer. There's an argument for pushing higher conversions on a limited market segment rather than trying to convert a lower percentage of all visitors.
> 5. Fear of knowing that there are unknown unknowns which will come at time of launch and bite me in the behind.
Learning opportunity! If they're unknown what are you afraid of? You don't know it, so how can you think of it to be afraid of it?
> 6. A hacker or spammer will take down my site.
Backups solve that one. Or you can get something like CodeGuard, which monitors your site for code modifications.
> 7. Fear of the fact that I havent thought of every possible outcome.
Why do you need an exhaustive list? Have you at least thought of the most likely scenarios? If something comes out of the blue it's because of your #5, and you can't ever predict for something that you don't know is coming. But if you have the most likely scenarios covered you can plan for how to work with those results.