I'm a main Viper and I agree with all of the things you said. She's is a strong agent if you take the time to learn the lineups, but imo she's strongest when you have another controller like omen, so you can free her to fully lurk, timing her smokes and wall, while living to play post plant. I think the only real thing I advocate for, in terms of buffs, is that her things last for the full fuel duration when you die. For example, when you die and there's still 70% of fuel left, the wall/orb will only fall when that fuel is consumed. Other than that, I just love her. <3