website testing process

Hi EE,

We are are trying to setup a testing process internally for our website development team to review websites before they go live and we hand over to the client.

This list does not include SEO testing or reviews.

If you have any ideas, missed steps or other online providers than the ones listed below, that would be great.
Some steps are repeated.

Following are the steps in order.

1. Developer to review and test the entire site using their chosen tools. (comparing against Photoshop files provided)
2. Designer to manually view on desktop, mobile and tablet. (chrome browser, iphone 6, ipad air, galaxy tab) These are the physical devices we have in the office at the moment. (comparing against Photoshop files provided)
3. We carry out Mobile responsive testing here http://quirktools.com/screenfly and http://www.responsinator.com/
4. We add content to the site.
5. Designer to manually view on desktop, mobile and tablet. (chrome browser, iphone 6, ipad air, galaxy tab) These are the physical devices we have in the office at the moment. (comparing against Photoshop files provided)
6. We carry out Mobile responsive testing here http://quirktools.com/screenfly and http://www.responsinator.com/
7. Page speed and performance testing here https://developers.google.com/speed/pagespeed/insights
8. We carry out a mobile friendly test here https://www.google.com/webmasters/tools/mobile-friendly/
9. Check markup validity with http://validator.w3.org/
10. Check css with http://jigsaw.w3.org/css-validator/
11. Testing of all contact forms.
12. Install wordfence security plugin and disable cache during developing testing.
13. Send to client for review. Reviewing and providing content is the sole responsibility of the client.
They need to approve before going live. after all, the client knows their content and business better than we do.
They also need to spend some time testing each page before sign-off.
14. We make the site live.
15. Unless under a maintenance contract, we don't have any further involvement with the client (other than with sales staff)

Any notes would be appreciated.