Oh well, sorry I couldn't answer in time!
2 days ago a thunderstorm brought my internet down for the first time in 3 years, I had canceled my then useless backup internet which became double the price for no good reason and my third backup internet on 3G is just not working as it used to.
Anyway, all your problems look to be simple enough to fit my minimum charge of U$91. I would just need access to your site to be as quick as possible. If you think there's still time, just reply here. I'm still without internet at home but for today I'm somewhere else!
In any case, here are a few pointers in case you want to do it yourself:
This works with no library dependencies. All you've got to do is find the container around your content and add that to line two of the script as the selector. (Note: in this case the selector is
var elems = document.querySelectorAll('#canvas');
(3) I'm not sure what you mean by that. Squarespace is made to be responsive in the most awesome way possible. But you can customize the layout, each template offers different options: http://help.squarespace.com/guides/making-style-changes and, using CSS, you can pretty much change anything indeed, but I need to better understand what you mean.
And if you feel this have helped you in some way, please remember to make me a contribution.