TheSearingTouch Fireball templar. question on priority order of dmg nodes

Hello

I have a fire ball templar and this is the spec I am at atm

http://www.pathofexile.com/passive-skill-tree/AAAAAgUAAnEEBwSzBVsHYwj0DH0OSBB_EZYUTRZvFr8ZhRpsHwIkqiepKU8tHzbFNtg26TrYO-FG10yzTdhVxlcrXcZd8mBtYeJtGXBScNVzU3kDfll_xoFvgh6Cm4M4h2WH24t6i4yMdo9GnC2dY52Ana6ePKKjpwinK7iTwFHAVMHzxp7PZdDQ2CTbC93z4XPi9-Nq44TkIuWO7DjsVe0g8Wzz6g==
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and this is the end goal in the late 80s, 90s

http://www.pathofexile.com/passive-skill-tree/AAAAAgUBAnEEBwSzBVsHYwj0DH0OSBB_EZYSaRRNFecWbxa_FxwZhRo4GmwfAiQ8JKomlSepKU8tHzGINsU22DbpOtg74UbXSTtJUUyzTdhVS1XGVytabV3GXfJgbWHiZk9tGXBScNVxeXJ-c1Nzs3kDf8aBSYFvgh6Cm4M4h9uIQot6i4yMNox2jmSPRpBVnWOdgJ2jna6ePKIAoqOksacIpyunXKeEsji2-riTwFHAVMHzxp7PZdDQ1U_YJNsL3fPed-Fz4vfjauOE5CLljuw47FXtIPAf8Gvw2fFs8h3z6vem_Ks=
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I use the searing touch staff and play softcore

Wich dmg nodes should I take 1st? the burn dmg? the crit nodes for burn and dmg? finish the shadow side of the tree?

At the moment I dont have issues with my hp even if I am missing several hp nodes
i run haste, deter, grace, clarity, disc, artic armor and molten shell
I use endu cry, fire trap and flammability aswell

I atm only have a 3l in my staff and its with Fireball+LMP+LifeLeech
planning to go for a 5l with Fireball+LMP+LifeLeech+FirePen+ChanceToIgnite(or FasterCasting, or EleProlif)

and ideally go Qfireball+Qfirepen+lmp+lifeleech+fastercasting+eleprolif

-Shuh