Based on what I've seen, I'd guess you're probably pretty close. I don't know if the D&D Miniatures stats are particularly representative of the RPG stats, but in that game we see things like several 12th level dwarves with 80-85 hp. Creatures in that game have a rough average of 7 hp a level, with a greater average at low levels and a lower average at higher levels, which seems to indicate the presence of a "kicker", as you suggest.JohnSnow said:Let's assume that a 1st-level Fighter gets a first level "kicker" of 30 hp. Let's further assume that he gains 5 hp per level after that. If we also give him a +1 CON bonus (12 or 13 CON), that means 6 hp per level.
You probably won't have to wait too long to find out if you're right. I'd expect that this sort of thing will be much easier to figure out after we get information at DDXP. At the very least, the (pre)release of the new miniatures set, with 4th edition roleplaying stats on the back of the card, should give us a representative sample of creatures and characters over at least the first dozen levels.