You are probably correct regarding the flamers however, deepstriking them as 6 would mean that they couldn't all fire their templates anyway, I shall do some experimenting as they tend to be most effective when they deepstrike. I preferred 3x3 as they would "seem" less threatening that a large squad of 9. This ensures to me in my mind that better/worse than average rolling isn't going to make me lose too much more than statically average and if they were to get focused down, they'd be focused regardless of 9 or 3's.
Daemon Princes and lords are expensive, I agree they are more durable, not withstanding, but needs be behind the aegis the heralds will be a line deep in horrors and go to ground for a 3+ cover save.
The Chariot is a Fast Open topped skimmer, and they can move combat speed (12") and the guys inside if you had gunports can fire their weapons at full range. A chariot is a fast open topped skimmer, the exalted flamer is the man inside or "on" I would suppose. Therefore he can still move his 12" and shoot the pink/blue flames.
This is the same as Dark Eldar for example in respect to travelling in and assaulting out of open topped vehicles and the like, the 12" move doesn't stop you from shooting.
The difference between the chariot and a regular fast skimmer, is that the chariot is also a chariot. This sounds obvious but makes a difference in combat. For example the chariot with an EF and a greater reward per say could charge a unit of lets say conscripts. The conscripts are Str3 with no krak grenades to speak of, therefore can not kill your EF because they have to destroy the chariot first leaving you to run amok so to speak. You can also deal impact hits on the charge and maintain an assault unlike other vehicles.
Regarding warpflame i'm not too scared of it. Most none
meq armies have a lot of Toughness 3 and you can't get
FNP against instant death (double your toughness) so
Str 6 powers and
Str 7+ weapons laugh at your misfortune.
Toughness 4-5 armies tend to be much more elite/small unit based where focus weight of fire removes them. 7D6 average shots rerolling statistically kills 4-5 space marines. whereas the return fire from that squad at full range is about 2 dead horrors. Although my attack can be denied on a 1/6

and tyranids can cause me a headache.