If you're planning to join Trans States or any other airline via an ad that has not been provided directly from the company, then they are hustling for referral bonuses.
Do you have any friends at TSA or any other airline you're applying for? Maybe offer them your referral first. Anyone can provide the same advice that has lived through the procedure, plus you might be able to split it with them. Alternatively free information is also plentiful in this thread.
To be clear, I think someone should refer you. After all, It's free money. It's just up to you whom you want to give it to. These agencies might be transparent about what they are up to, but also might not be.
Dangling the Frontier flow carrot makes me instantly wary. E3 holders try and fail over and over again with the LCCs. Please don't choose TSA based on this.