Even a lone sturmpio squad will do significant damage to it. It's so weak in terms of HP, it's not useful - you can engage only one squad with it, if he has another squad nearby you will just take too much damage and repairing it takes time. Within a few minutes he'll have schrecks around and it's useless. It's not worth the fuel cost let alone going for a T1 based strat for a flamer clown car.
Against ostheer, it's dead if you get fausted even once.
I pretty much agree with you. Some points were obviously correct, eg faust-death.
I think you're underestimating its role in stopping harassment and wiping units on retreat.
Do you think the Kubel is substantially better? I don't see it. If you put in flamer engies, you have a stronger, fast capping unit with more firepower that's not much more expensive. I'd honestly take the scout+flamer over the Kubel.