So I'm choosing between nikons 35 1.8 lens, or nikons 50 1.4 lens. I don't need advice about optical quality
or so because I know both of them are good - the 50mm got some CA though but that doesn't matter so much.

The difference is that 35mm represents 1.0x zoom, while 50mm represents ~1.4x zoom.
Which one would you find most useful? And why?
I will probably sell of the kit lens 18-55 because of the not-so-good light sensitivity. I do have a tamron 90/2.8

I'd go for the 35mm, I use a 50mm 1.7/f and it's awesome, but I have got into some situations where I needed a wider angle and couldn't get it.

What do you like to take photos of?

as I do bring my camera about everywhere, I take photos of everything that looks like a good shot

I'd go 35 for width.

theyr lenses for different things. i would take the 35mm because personally i like to use that focal lenght more(on that crop factor your camera has). 50mm on that camera is more of a portrait lens, it can be used for other stuff too, but its a small tele lens(with that cameras crop factor), while 35mm is "normal" lens. Test them both in a shop and think what you want to use more. im pretty sure that the 50mm has better image quality, not to mention its f/1.4, not f/1.8, so it lets more light in and gives better dof(because larger aperature and longer focal lenght). For overall shooting 35mm is better, but since its just one focal lenght(no zoom) it wont cover all your needs, so take your kit lens with you too. What compliments the kit lens more is another thing you should coinsider, because you can get both focal lenghts from it, but you cant get the small f-numbers out of it, small f-numbers you need for dof and naturally it lets more light in. That tamron you got is good for portraits allso, so imo you dont need 50mm portrait lens with it, but if you want the dof at 50mm, thats another thing. If i were you i wouldnt sell the kit lens, since you will miss wide angle without it, unless you buy third lens thats a wide angle. The kit lens is so cheap that its not worth selling imo, since you will lose wide angle, maybe sell it later if you want to buy a better wide angle lens someday. One thing you should think about is wether you want the dof and ability to shoot in darker at 35mm or 50mm. Sigma 30mm f/1.4 would be a great choise, but i think that costs bit too much.

Neither of the lenses represents eny kind of zoom, they represent different angle of view, that angle is same even at full frame camera, but the frame is cropped.

hopefully this helps or atleast makes the decision more harder so you end up picking the right lens.

Yeah, I've pretty much taken the same conclusion
The 35mm already has good enough light sensitivity imo
You got a point about the 18-55, I'll keep it until I notice myself not using it anymore

light sensitivity isnt the only thing that you should look at, you can use longer shutterspeed with 35mm without hand shake showing, than with 50mm, so the amount of light you can get with these lenses is about the same. when you use 35mm with lowest possible shutterspeed that you can hold steady, it wont naturally stop motion on other things that do move, so you wont get sharper pics of things that move with the 35mm. When you use 50mm with lowest possible shutterspeed that you can hold steady, it stops motion on other things that you shoot at better, with same amount of light getting on sensor. The difference between these two isnt significant, but it makes a difference, since both are on the limits on stopping down even really small motion, with 50mm being better on this. You might need to use the shutterspeed of the 50mm on 35mm in most situations(where you would frame the same way) enyway if the movement of objects(or people) is just bit too fast and it usually is with the minimum shutterspeed you need to use. What comes to lens being light sensible enough, for me even 6400iso and f/1.2 on 50mm is too slow meny of the times to get the desired shutterspeed, thats same as 12800 iso with f/1.8.

10mm