Shadow Noob Requiring advice on Tree.

I need advice on my tree. I am playing as a Shadow, and this my level 41 tree.

https://www.pathofexile.com/passive-skill-tree/AAAABAYAAAceDkgRLxGWFr8byCHAJpUrCjY9RXxUR1VLXfJh4mKsaoxsjG1scFJ1_YRvidOMNpUul5edqp7EotmmvrDYtUjIFMu9zerP3eLV5oHndOjW62PtQfDV8Yr1bw==

I am asking is it possible to create a Ball Lightning OR Herald of Thunder+Arc OR Blade Flurry OR Essence Drain+Contagion build going on with this setup ? Or should I respec anything? I can pretty much roll over any mobs right now in Normal Difficulty except during Master's Daily Missions (eg. Tora), but I am not sure if it would work out in later levels.

Any help will be appreciated. Thanks in advance for any reply.

PS. I don't know how to link socketed Items and gear in posts. So I can't tell you which gear I am using right now.

The skills you listed are very different in machanic and the way they scale. So you should choose a skill that you want to play and build around it. Any of the skills you listed can work as a Shadow, you just need to pick one.

Yes. I know any one will go on to work but when compared to my current skill tree, which skill combo should i go to?

Ok, let me be honest: at the moment, your tree is a mess.
Respec the elemental damage, go crit and physical, grab that large life node then proceed to force shaper. From there on, grab the dagger wheel on the outer part of the shadow area and go blade flurry.
Going for a different skill wouldn't make too much sense at this point, as you already invested quite a lot of points in crit, phys, chaos and even one handed damage.

Your basically sclaing all the skills in your tree right now. If you want to play either Ball Lightning or Arc you should spec out of the Physical and Chaos Damage nodes in the Shadow start.
If you want to play Blade Flurry or Essence Drain you should spec out of the Elemental Damage nodes in the Shadow start.

Example tree for Arc / Ball Lightning
Example Tree for Blade Flurry

If you choose a skill now that you want to play we can help you to modify your tree to it. By the way, you can go to your profile -> privacy settings -> uncheck 'Hide Character Tab' so we can have a look at your character's gear in order to help.

Okay... I suppose I did go a little wild with the choices I had....

I think I should respec the elemental nodes as they only apply for the Lightning builds I suppose.
But what about Blade Flurry? If I go that direction is it viable to later spend some points in improving Essence Drain+Contagion combo? Or should I completely abandon ED+C direction as well?

Also is Blade Flurry viable for crowd control and boss fights both?

PS. Have changed Inventory to be visible.

Both Blade Flurry and Essence Drain + Contagion are very good builds, but they each take their own path. ED + Contagion is scaled via Chaos Damage and Spell Damage (and you would go for the Trickster subclass), while Blade Flurry is scaled via critical strike chance and damage, aswell as physical damage and attack speed (and you'd play the Assassin subclass).

You're at a point where you can decide for either one, but you have to choose.

And Blade Flurry's viability for Boss fights and Crowd Control? I suppose it is a good crowd-control but what about Boss fight?

Blade Flurry has extraordinary single target damage. However, I think that Essence Drain + Contagion has a higher clear speed. Although the difference isn't that noticable.

It pretty much comes down to what you prefer playing.