This is what I would like to see changed in Insanity myself:
1) No Medkits beyond safe room Medkits.
2) No Defibs at all!
3) Smoker Tongue health decreased, it's got too much hp at the moment so it's almost impossible to kill it with ranged weaponry. I agree with buffing it (breaks too easy in Vanilla) but think it's buffed a bit too much as it is
4) Reduce fire damage a bit, it's a bit too high as it is imo, I think it would be better if it did around 25% less damage (still deadly, but unlikely to kill you instantly.)
5) Try and reduce melee damage tank takes
That's my 2 cents anyway, interested to know if anyone else agrees with me