Don't think so. Animations must be imported as rendered video files.

No. you can use image sequences and i believe gifs too but not sure

You're going to have to do that to an extent with any character generator system. The Adobe ecosystem and live broadcast systems are very different things.

My art director comes up with cool things in After Effects to demo. It doesn't automatically mean it's practical in a live broadcast setting (in this example, he flunked with the notion of headroom), nevermind the system it has to go into (that being a really expensive Chyron).

At a bare minimum, you'll have to build the text boxes in GT. It's really not a realistic expectation to think things like that export and import seamlessly.

As mentioned, utilizing image sequences is your best best for bringing in elements. It is a very reasonable and common way of doing things. There's even a preset in Adobe Media encoder for PNG sequences, which by the way, is also useful for stinger transitions.

vMix posted a tutorial on this very topic:
vMix GT Image Sequence Tutorial

This is not an unheard of challenge. I will caution, however, that you might be in for a bit of a headache if the agency isn't doing things with broadcasting in mind. Print and web are very different beasts and are prone to not translating well.