What changed in the latest theme update & how can I fix the problem its caused?

Hi HB,
I just updated the theme on my corporate website and unfortunately now see there are lots of items that no longer work properly. Could you please let me know What has changed on the new theme, and how do I get back the previously working functionality?
Here are the main issues:
My logo used to be centered on the screen. It is no longer centered and seems to have been resized to a smaller than required size. How do I fix this?
Where I previously had revolution slider elements starting on almost every page under my website menu’s, there is now about an inch gap between the menu and the start of the slider. How do I fix this?
Where I use a four column menu (Consulting Services), the sub-menu items previously started under the menu header, now they start over the top of the main menu item so I can no longer see the main menu item. How do I fix this?
The image that showed as a background behind my logo used to stretch to the page width, now is is tiled. How do I fix this?
My footers and legal information seem to have totally disappeared and I cant find them anymore. How do I fix this?
My website is http://www.gcp.asia
I was using v1.7 HighEnd Theme and just updated to 2.4.4
Thanks, Gavin.