XF 1.4 Invasion of body element

Hello, a newcomer here. Got too frustrated of MyBB so after ~15 years of various free forum softwares I finally jumped to the paid forum vagon.

TL;DR: can I easily change all JavaScript that generates elements to the end of body element to instead be generated inside a container element of my choosing? If so, where to look at?

I have this issue because I want to wrap XenForo inside a container element. I don't want XenForo to have any control of the body element. Ideally I don't want any xF CSS to touch anything outside the container the forum is in.

At the moment XenForo's CSS reset and lack of classes on elements such as headers causes me styling troubles in many ways. My design philosophy is quite different from xF way of doing things, as I base the site design on normalize instead of resetting everything and I give CSS classes for almost everything so generic styles don't leak all over the place. To really properly fix reset issues I'd have to remove all base resets and instead give those rules to the CSS classes that actually need a reset. However as a temporary solution I'd simply want to do a quick retarget so that I don't need to spend all of my weekend just fixing CSS. Which leads to the question I have.

If you're wondering why I want to have control of body element you can take a look at the currently running MyBB installation. It's not your standard looking software. I got started with xF a couple of hours ago so I don't have anything live yet.
Resolved, kind of: I'll simply not have xenforo_reset.css and xenforo_basehtml.css included, and instead I'll include a custom CSS that does the minimal required resets to get all XenForo's classes looking proper.

The above message didn't go to waste though, got me thinking about the best way to solve the issue :)