Here's a fun template:
50 Thrust (Dragonfang, love you some evade)
50 Dual (Dual Shadows for anytime)
34 Crit (PA to Creeping Death for stun, don't need the follow-up because bleed is lame)
33 Stealth
2 Env
But that's just me, having never played a merc or merc-specced Infil. Your poisons will never stick with 2 env, even with max +'s. As such, you'll want a lot of +con and +hp gear, because your fights will last much longer. Buy Dodger as soon and as often as possible.
(I'm assuming you're going to try to keep stealth at 1/2 level, otherwise you won't be able to make use of the crit styles. With a melee-heavy template, you should be able to let stealth auto-train, if you can rely on getting xp from grouping).
Lvl 5:
2 Thrust, 2 Crit, 4 Dual
Lvl 10:
9 Thrust, 6 Crit, 8 Dual, 5 Stealth
Lvl 15:
12 Thrust, 9 Crit, 15 Dual, 7 Stealth
Lvl 20:
17 Thrust, 15 Crit, 18 Dual, 10 Stealth
Lvl 24 (BG1 cap):
21 Thrust, 21 Crit, 18 Dual, 13 Stealth
Lvl 29 (BG2 cap):
21 Thrust, 29 Crit, 22 Dual, 16 Stealth
Lvl 35 (BG3 cap):
23 Thrust, 34 Crit, 29 Dual, 21 Stealth
From there you'll want to split points between Dual and Thrust (preference for Dual until it hits 39 around lvl 38), with leftovers into Stealth.
That's *if* youwan to try my untested Mercfiltrator template, designed by someone who hasn't played a Merc or merc-specced Infil ;)
if you do that your taking away your ability to do the long duration stun with dragon fang because of the 1 min rvr immunity...if im not mistaken
from what ive read on the vn boards most mercfiltrators keep CS down very low...like 11 (i think) for backstab 2, and only really use it to pop BT. most of them also seem to bring envonom up...str/con debuff, DOT, and root poisons are just great things to have.
those are only my impressions though
Seriously tho, you'll have to decide whether the PA -> Creeping Death chain is more reliable than Evade -> Dragonfang. One is reactive, the other proactive, I can see the benefits of both...
However, I hadn't realized that Infils can't but Prevent Flight like Mercs can - without PF and without Snare poison, you may have trouble chasing down your prey once you've popped them.
50 thrust (of course)
50 DW (ditto)
35/36 stealth
7 CS
30/31 Env (enoguh with some realm lvls to give 45 for the second best dot)
lets face it, no envenom = no Snare, no str/con debuff.. you can still get a dot of a proc, but not these.. i would recommend against dropping that to nothing
i AM considering this spec for desa, once i get to realm lv 5, so that my stealth will be capped at 50.. id also like to test the impact of body resists on Lifebane, see if its still worth it.. cause you can still have Dual Shadows AND Insidious Lethal Venom (45 Env)
Consider this spec for a mercfiltrator.. just take my advice from playing an inf:
1. DONT Do like Greydark.. Do NOT hinder your stealth.. An inf with 26+11 stealth is not enough.. you might as wel have 0.
2. Dont Let Envenom drop.. Theres so many situations when ive been in absolute crap, took out my backup imbalance poison blade, Snared the guy looking for me and made a run for it.. its a great backup to have.. Disease poisons are also great for raids, to use on Npc archers etc..
So these are my suggestions to Amber and Sodom..
always rember that i am god and my counsel is the law...
THIS I COMMAND!!