Can I check if cookies are enabled for example?
Yes, but not as easily as you think. navigator.cookieEnabled is a very general flag which does not cover exactly under what circumstances you may set a cookie.
For example, it's possible for session cookies to be allowed but persistent cookies blocked. So you're not really going to know whether a cookie-set will succeed unless you go ahead and try it, by setting a dummy document.cookie and then reading document.cookie back to see if it took.
In many browsers a persistent cookie will be downgraded to a session cookie when persistent cookies are disabled. But not IE, which will simply block it. You can try to detect that by setting both a persistent and a session cookie to document.cookie and seeing which if any survives.
