step 3: read what amount of hp you gain from vitality mastery upgrade skill, to keep it simple lets say 400 hp you gain from it. this means you have 2900-400 = 2500 "net hp"
step 4: 2500 * 0.4 = 1000
this means you have a maximum death penalty of 1000
so you can have 1500 hp when you wear no gear and you have maximum death penalty

if you want to verify this:
i just went running in lakeside with mortalbane to get cabal alz
when i died, just went back running to orcz in mortalbane
did this till my death penalty was maximally (when it doesnt rise anymore after 5 deaths in a row r so)
than i saw if i took the mana number and played with the numbers of my current amount of mana and my amount of "mana-dp" i saw that it was 40% of my max mana that i lost
than took off all gear and saw i came out a strange amount which wasnt that logical as a percentage or so,... than lookd at any possible reason, and found out that if it was a difrent percentage, that was a "round number" like 30% or so, it still wasnt the correct cabal alz,... than lookd at my vitality mastery upgrade skill, and saw if i did away that number too, it came out exactly at 40% maximum death penalty.

i didnt verify yet if this percentage is class specific but i think its not,... for shielders it is 40%, and for other classes i assume its the same,... but that still needs to be verified,... if some people want to try this too,... (i could just make a noob char too, but if you have only 50 hp or so, its not very convincing ;p and you dont see that the hp bonusses you get from those level rankup quests you get every 10 levels dont affect the numbers) for shielders i verified this on my fs (level 130+ when i tested it) (the cabal alz of hp you get per levelup is diffirent for fs/fb, wa/bl and fa/wi too, so maybe its 35% or 45% for those classes)