Help with build

I liked to play with traps and mines,and to finish off mobs on melee,so my skill tree had both trap damage and physical damage nodes.The damage was pretty high,despite some survivability problems.But I was heavily discouraged to "hybridize" my build to the endgame.So I was thinking,what if I take mostly general physical damage nodes,just some dagger-related nodes,critical strike chance and multiplier,and using ethereal knives and bear trap,while fighting melee?Would something like that work?As ethereal knives and bear trap is purely physical damage

Forgot to mention,class is Shadow

The biggest problem with scaling two different sources of damage (like a spell and a melee attack) is the fact that your weapon will only benefit one of them. For ethereal knives you would want a wand with a large amount of spell damage and cast speed, whereas for a melee attack you would probably want a dagger with physical damage, %physical damage and local crit chance(which does not affect spells). So even with mostly physical damage nodes in the skill tree (which do affect both) one of them will be significantly stronger than the other based on your weapon type and rolls.

That being said it is definitely possible to make something like this work. If you use the hatred aura you can scale both your melee damage and your spell/trap damage at the same time. There are three ways I can think of to scale both a melee attack and a spell/trap with the same nodes.
#1) physical damage nodes. As you said you were focusing on getting these but be careful that they are just physical damage nodes and NOT melee physical or physical damage with daggers as those nodes do not affect spells.
#2) hatred aura. Hatred is the only aura in the game that adds extra physical damage as an elemental type. Herald of ash also adds some physical damage as fire, but only applies to attacks not spells or traps.
#3) lots and lots of critical strike and critical strike multiplier. Any skill (except shock nova) can be viable if you stack enough crit and crit multi.

Overall I would recommend not going hybrid melee/spell because no matter what you scale it with you will not achieve maximum efficiency in the skill tree, however since you seem pretty dead set on it, it's totally possible to make a legit build that uses both. Focus on those 3 primary ways to scale the damage of both your melee attack and your spell but don't forget to pick up lots of life nodes and if you get enough crit you're going to want to pick up vaal pact as well so you don't die instantly against reflect mobs.

To be honest,I prefer to limit my build potential and have more than one damage source at time,so I can in fact play the game,and not press a button and watch everything getting auto-slaughtered in my screen.So I don't care if it will not reach full potential,if works it's enough for me.I am thinking on using traps with EK and bear traps with multiple traps and increased area of effect,but I don't know yet if this would work.

So,I can't thank you enough.You just said what I was wanting to read,"possible,not a top build but possible",and that's enough for me.Thanks for the help and for your patience ^^