Speed up website, check performance, 2 Divi customizations, Front End PM Customization

I'm about to be done with a website I designed for my father-in-law. When I first started a few weeks ago I just wanted to learn how Wordpress works to create my own blog. I like the way it turned out and I want it to be a fully functioning website. Here is what I need: 1. Speed up the website. The speed tests shows things like: - minimize redirects - leverage browser caching - reduce server response time - eliminate render-blocking JavaScript and CSS in above-the-fold content I have a very brief understanding of what they are and I tried to eliminate some of them but it didn't work out very well - optimizing plugins messed up certain features of others etc. 2. Customize Divi's post grid. - I would like to be able to use divi grid option on pages, custom post type I created (disease database), and if possible even on categories - to display a grid of categorized articles (e.g. Health News category grid, Supplements category grid, Mental Health category grid etc.) 3. Customize the Tabs section from Divi's library ...so I can add another section in each tab (mostly the grid) OR be able to create a short code of grid so I can just place it in each tab. Which ever is easier to achieve. 4. Customize Front End Pm plugin so it fits the theme. - Add button "Message Dr. Bergman" instead of having a free option of emailing everybody - Display attachments in the email body rather than having to download each of them separately in order to see them 5. Help setting up new hosting I started with Godaddy managed hosting just to see how everything works, speed test kept showing "reduce server response time", so yesterday I changed it to a faster one - business hosting, also Godaddy. After the migration was completed I got the email from Godaddy support with further steps (change the primary domain on cPanel, DNS for the domain/subdomain can be pointed over to your new IP address etc.) and I did it all, I'm not sure what went wrong though because the website is blank now and it just says "pageok". I called Godaddy support and they couldn't help. I would appreciate a professional opinion on functionality of specific plugins, changing them to others, or just anything that I've missed etc. Important: Time is pretty important to me. I want to launch the website January 1st but the only really crucial is "scheduling skype consultations" section which is ready. I'm still working on the rest of the content so I think it will take me at least a couple of weeks to fully finish other sections. Until then I may just have simple "coming soon" pages on sections that are not ready or the ones under constructions.