Testing and real in the field combat is completely different. When you are getting hit you fingers will slip and you will not heal for anything close to this.
You are MUCH better off to have a 4/6 Chiv guy. My template is
120 Fence
120 Ninja
120 Tact
80 Poison*
90 Chivalry
80 Stealth**
110 Hide
* I sometimes swap out this for 80 Parry and use Shurikens if I'm fighting a lot of dexxors
**Not sure why people think they need more than 80, you never fail at 80 and the little extra damage in PvP because of cap is not worth the 40 points. You are better off putting the extra points in Hide because it's the same damage calculation and Hide allows you to Hide while closer to someone.
I have 90 Chiv because I use holy light for a super fast interrupt and dispel evil against summons mostly pixies.
I agree with some points, but disagree on many others. I doubt anyone (at least that I've seen on any shard I play) has put the time into testing (in the field) Assassin builds that I have.
I agree that with any Ninja assassin build you are going to want 4/6 chiv, and at least 50 chivalry. It's more efficient for a skill point cramped template.
You said you have 110 hide, I didn't know you could go above 100.
Having had an assassin using poisoning, I would suggest using shurikens and NOT infectious strike. 80 skill points can be completely negated by having a potion.
I wouldn't suggest going over 60 chiv, at 90 holy light isn't reliable enough to count on for a disrupt.
As for 80 vs 120 stealth. It's a tough argument. 75 stealth is enough to never fail stealthing in medable armor and frees up 45 skill points. However, let me tell you this. 120 stealth, 100 hide, and they are tracked, if DS'd two times consecutively and an evil omen hits the target before their 5th step, you do 75 damage. If deathstruck once, tracked, and evil omen before 5th step you do 60 damage.
The assassin is designed to use the element of surprise and kill them before they realize what has happened. In order to do this you need to do as much damage as possible in a short time before your opponent can react.
With the build I use now, I've killed people in 2 swings and 2 spells. They never had a chance because my RNG worked.
When I have one of my guildmates on a supporting stealth archer, we succeed at 99% of our assassinations.