The example HH you gave means V can never be solid. It is a disaster through and through. It shows he's bad passive and bad aggro, and doesn't have a solid grasp of the game.
It also indicates that he is a bit sticky. Why are we trying to bluff away a bad/sticky opponent?
Flop and turn are kinda OK since we aren't risking a ton, we have equity, we might get paid from this V if we drill it, and hopefully we have at least some FE.
Since we've seen firsthand how bad he is, his range could be pretty wide here. I suspect a lot of Kx, some Jx, a lot of FD's, maybe some slowplayed 2 pair/sets (since he's obviously not the greatest player), and a few straight draws (mostly T9?). But as wide as his range is, it's not ATC, since he prob isn't going to call pre, float flop+turn with air.
Betting this river specifically (or almost any river) is poor opponent assessment on our part. There are parts of his range he'll fold. But unless he's at the bottom of his range, it will take a large sized bluff to induce a fold, which I think is way too risky to be EV+. And the smaller bet just gets called/raised way too frequently.
These are just my thoughts. I always welcome dissenting opinions to see if I ****ed up somewhere, so I can try to learn.