Okay, I think I have all the pieces to this one...
Role 1: These people do things in mountains, pastures, hills, fields, forests...
SETTLER. The listed location types are playable spaces in the board game Settlers of Catan.
Role 2: These people do various things. They can find you a house, a hotel, send you something, kill you...
AGENT (as per @JohnLaRocque's answer: "real estate agent, travel agent, mail agent, secret agent").
Role 3: Atom....in English
INDIVIDUAL - you can't really get much more 'individual' than a single atom. We even use the adjective 'atomic' to mean "of or forming a single irreducible unit or component in a larger system" (Source: OED).
Now, as to who might be 'the one with the above roles':
I believe from a lot of Googling - boy, is someone going to have some fun with my search history now - that being the 'Settler, Agent and Individual' is something to do with citizenship or legal terminology, with particular connotations to the 'Sovereign Citizen' movement in the States - a group who rejects federal law and refuses to be bound by it.
In which case, the role that is missing may well be:
The PERSON, which web-famously features heavily in a probation hearing between one such 'citizen' and a judge in a video and transcript from 2014 which occasionally goes viral every now and then and does the rounds on the Internet...
This would fit with the title too since:
The judge in this particular viral video is Judge Hurley, hence the use of 'hurl' in the title...