To make it easier for the beginners and the host (Lúthien would have to explain about the dialogues) I opted to change this one sentence: Haeron i ven gîn to avoid the predicative adjective.
I thought to supercede it with: You walk a long way. - Padag ven ann.
EDIT: I changed the position of the sentence as well to give the conversation a more natural flow,..
Guilin: "Mae govannen, Lindir."
Lindir: "Mae govannen mellon nîn."
Guilin: "Padog na mbar gîn?"
Lindir: "Mae. Padon i ven thent."
Guilin: "Renion n' amrûn, na Thranduil na Daur-nu-Fuin"
Lindir: "Padog ven and. Lend vaer, Guilin."
Guilin:"Cuio vae, Lindir!"
Guilin: "Well met, Lindir."
Lindir: "Well met my friend."
Guilin: "Are you walking home?"
Lindir: "Yes. I am walking the short road."
Guilin: "I wander eastward (towards the east), to Thranduil at Mirkwood."
Lindir: "You walk a long way. A good journey, Guilin."
Guilin:"Fare well, Lindir!"