This cannot be restated enough. An SSL cert costs anywhere from Free to $10 and is invaluable for the logged-in section of your site, and an absolute requirement if you are handling any kind of payment.
The item is phrased badly, however. You need to have HTTPS on the entire site, not just the login page, or the user's session will be vulnerable.
Instead of compressing a few files on disk, compress everything on the wire—make sure your server uses Content-Encoding and Accept-Encoding.
> 9. Spell check your website
...I see what you did there.
Remember you are not making the checklist only for you. If you work for a company they need to have prove that the checks have been done correctly. This is a form of auditing.
Also, if you reduce the text on that list then you have a checklist. So basically you generate 2 separate documents. One is the checklist, other one explains it.
They read like advise on how to do things, rather than a list of things that are required to do before you launch.