I've all of a sudden fallen in love with Iron Man and i'm curious if he has ever killed.

He did when he was under the influence of Kang.

Avengers The Crossing

Of course he did. He created a clone of Thor, which makes him responsible for the death of Bill Foster.

yes he killed mallen I'm searching a scan but can't find one.

I don't think he has intentionally killed.

He killed him becuse he was to big of a danger and he said he never would stop. (well i remember it that way)
so he grabbed mallen's head in his palms and activated his repulsorrays wich caused his head to explode fatality style. Tony was upset to kill him but he felt it was his responsebility.
sorry if there are faults i'm not english.

" Of course he did. He created a clone of Thor, which makes him responsible for the death of Bill Foster. "

mallen, gremlin (the titanium man in armor wars), and in demon in a bottle justin hammer had control over his armor and made him fire a repulsor ray through the man introducing iron man at a speech

He killed Amanda Chaney, the publicist for his team Force Works..  He wasn't in control of himself at the time...
He killed the Inhuman Marilla, but he was controlled by Kang the conqueror at the time.
His CLONE killed Igor Vanko
He IS responsible for the death of Bill Foster because he and Reed Richards created the Thor-clone that killed Foster.
It was 'implied' that he pulled the plug on Happy Hogun, his former body guard and the man Pepper was in love with... BUT she ASKED Tony to do so...Happy was being kept alive by machines.
 
I believe he has killed skrull and kree warriors during the skrull-kree war... and of course, many skrulls during the skrull invasion.

Tony also led the Avengers unit that killed the Supreme Intelligence.  Okay....The Intellgence survived, but they didn't know that at the time and they intended it to be permanent.

he once killed an entire liquor store's inventory 

He made an armor that grew its own AI and then killed Whiplash unintentionally.

He killed a random guard back when his armor had been stolen and did it right in front of Cap if I remember correctly.

He gave Mallen a Fatality

he killed a whole lot of skrulls.  
He killed Mallen in extremis

Mallen got killed pretty bad

didnt he basically take part in a Skrull genocide? (exaggerating, so please dont attack me)

You don't think those repulsors kills the thugs he uses it on? lol obvius.

In Extremis Tony Blows the bad guys head off, While he was getting his throat crushed..He Kinda Had to do it..

Stark was an arms dealer, some have claimed his weapons have killed hundreds of thousands of people!

He killed over a hundred terrorists whilst escaping captivity.

Yes. A lot of the times it wasn't his fault, being controlled or something. But yes he has killed intentionally.

Has he ever killed? Yes. Does he enjoy killing? No. Despite what MCU made you think, Iron Man reserves to killing only as a last resort, not the first option.