Yeah, you can in theory play this game completely free and earn all the tp needed for ALL content just with non-stop bang-your-head-to-the-wall grind.
Personally, I invested some to ease it, mainly a few months of vip to get all the perks, unlocks and riding skill etc for nine characters, one of each class. Just playing a character while you're VIP, however briefly, permanently unlocks a lot of stuff for that character. I also currently have each and every quest pack, and almost every skirmish, and I sure didn't get them all with buying turbine points. Some ungodly amount of grind was done, and waiting for stuff to be on sale is the key.
There's always new content coming, of course, I just did a small grind spree to get the Great River -50% off, even if I don't play a whole lot anymore.