Possible to replace default bullets in unordered lists?

Yes, use CSS to target the specific li elements you wish to change and use Unicode for the icons.

Here is the cheatsheet for all the icons: https://fortawesome.github.io/Font-Awesome/cheatsheet/

Your CSS will look something like this:

li:before {
	font-family: FontAwesome;
	content: '\f105';
	padding: 0 10px 0 0;
}

li {
	list-style-type: none;
}