Custom SSL allows you to upload any certificate from any certificate authority. This is mainly used to upload EV or OV certificates.
Bypass cache on cookie will allow you to cache your website’s regular HTML, but when a user visits a page with a certain cookie in place (for example, a cookie named
cart) CF will not serve the cached page and will contact the origin web server all the same.
In general, no. TTFB is how fast your own web server is after it receives a request. The most common causes of high TTFB are when the web server has too many plugins installed (too much code is being run on each page load), or the web server itself is overloaded/underpowered and can’t handle the number of people it’s getting per second.
Going to refer to the railgun promo page:
It’s a piece of server software you can install in your datacenter/VPS/etc which heavily compresses page responses and keeps a single TCP connection to Cloudflare instead of listening for incoming connections like regular HTTP.
In my opinion, the business plan is worth it for my business (50 free page rules are probably the best part), but it all depends on what you need and if the features shown on the pricing page would benefit you/your business.