Even with the increased visibility that was added earlier for players who are on fire, I still find the flame thrower almost completely debilitating during battle(as an alien). I usually end up running into walls or at the very least missing my mark entirely. There's a couple solutions I'd like to propose.
1. Have level three armor come with a perk that prevents aliens from burning. Seeing as the flamethrower is a pretty early game advantage for marines, this would be a late game solution for the alien team.
2. Make hivesight more functional, a la Left 4 Dead style silhouettes, which would let any alien see a parasited marine easily through the flames. This would also work with whatever flavor of "scent of fear" is added. What's nice is this would provide both early and late game solutions, the latter being more reliable.
~Otis B. Driftwood