Rose lives rue Poulbot, Paris, in the Montmartre area, famously featured in the French movie Amélie (2001).
The initialism "BFF" (best friends forever) can be seen on Thibault's tombstone. In his case, it could mean "Be Forever a Friend".
Bruno calls "Titi" either Fifi or Kiki (interestingly, a "kiki" can refer to a man's genitals, and Bruno says "naked on the beach"). It shows how little he cares about him.