PoE Shadow, Withering Step, Trap builds

Hi - I'm quite casual. This is the first league I've sunk a lot of time into the game in a while. I suck at dodging mechanics and need to be decently tanky to enjoy the game. Is there anything I can do to improve my damage on my build that doesn't break the bank? Should I realocate some points in my tree? I run despair on hit because I map and it's more a quality thing. I self cast despair/temp chains on bosses which I think overrides cast on hit (unless I misunderstand the mechanic) I have about 5 div but would be willing to farm more. [

BOSSING: You must have a Cold Iron Point, or a dagger with +1 Phys and Dot Multi to use blade trap. Obliteration is for mapping, CIP is for pinacle boss farming/completion

This is a build I'm planning to league start. It probably does and will suck. But I'd be happy for feedback on it anyway. Maybe there are other players like me who don't assume that all these fancy things people put on builds are attainable and want a no-budget ssf build, or this build may just be useful input to someone somehow. It's got 100% spell supp, 13k max phys hit, 90% evasion, and 110k dps. This is without shock, onslaught or power charges (though I am doing shock, onslaught and assassins mark on hit). It uses smoke

Levelling 1-12 - mule Splitting Steel with a Duelist start, link with Onslaught and Chance to Bleed Early links Splitting Steel - Onslaught - Chance to Poison / Chance to Bleed Key Act 1 Vendor Gems - Precision - Whirling Blades - Smoke Mine - Spectral Helix - Withering Step - Steelskin 12-55 - Spectral Helix - Onslaught - Chance to Poison (swaps to Added Chaos after Normal Lab) ^

18 masteries = 54% more dmg 18 es mana life per kill escape artist - soul drinker - polymath - spellbreaker ( overcharge support? )