It appears you have switched to Laravel. That framework should take care of a lot of security vulnerabilities automatically for you as long as you don't circumvent their procedures. You can of course make your own security vulnerabilities with code, so you should still be mindful of that.
I would argue that #5 and #6 of Master Coder's points are arguably not necessary to change. CDN's are pretty widely used and you are using some reasonably trustworthy sites. The one I might move into your domain specifically is bootstrap.min.js, although it's not a big deal either way.
The point of #6 is to prevent other users from logging into their account while using that users computer. While this may be a security vulnerability, it is also a choice by the user. You should not be overriding the users preferences unless you have a very good reason to do so. If you were protecting sensitive information such as credit cards, bank account information, SSN's, etc, then maybe consider preventing that, but even in that case, this is a user preference and you are counteracting features built into a browser. That's just my 2 cents there. This link (http://stackoverflow.com/questions/2530/how-do-you-disable-browser-autocomplete-on-web-form-field-input-tag) has some useful information on stopping autocomplete. Although you'll notice that Firefox partially ignores the rules of the autocomplete="off" tag and asks the user if they want to autofill.
With that, I will say you should make your own custom 500 page and put your Laravel installation into production mode / prevent error messages outputting to the user. Your 404 page could use some navigation back to the homepage as well.