Want to change templates on 7.0 to "York" but have a legacy template and like how the "Grid Gallery" floats up on current template – can I keep that when switching over?

Site URL: https://zmaic.com/#/sb-poster/

I really want to update my 7.0 site to "York" template, as my original one has been discontinued:
Why York?:

1. Like the mobile nav
2. Like the introduction headline option for homepage
3. More modern options for blog, store, etc.
4. Example of "York" I used years ago for a friend: https://www.havenpress.com/
    

What I DO want to keep is how the "grid" appears at the end of each project in my portfolio displaying all the projects. Example of my site: https://zmaic.com/#/sb-poster/

Questions: Can I update the mobile nav to look like York? I don't believe I can "show" the intro headline on the homepage… any thoughts? 

If you are using 7.0 you should able change your template to York template

or you want to change 3 problems above only?