Doesn't Thanos killed people because he's in love with Death?
Yes.
Would Thanos stand a chance against Thor or Silver Surfer without the Infinity Gauntlet? I only have a very basic knowledge of him so I don't know.
Yes. He can beat damn near everyone physically, but he goes out of his way to show he can outsmart people.
Basically if he's fighting someone that needs oxygen he'll take them directly to space and let them die there. He doesn't bullshyt.
Marvel made him so good they had to create Drax the Destroyer specifically to kill him........then they brought him back to life and he's stuck in another universe and he's immortal because death won't have him.
Also, if Bruce rode out the effects of the Omega beams then Thanos would take those no problem. They don't even kill.