How to set up nicely your pixel game??

Hi everybody, i need some tips on how to build a pixel game the right way.

my concerns are basically in:

1) can i make my pg in like 32x32 and my tiles in 16x16? or is it "bad"?

2) how do i setup the camera? i saw that to get the right proportion you have to set the camera size to "screen height / (ppu/2)" but if i do it this way then i see my screen "too much zoomed in". i tried the pixel perfect camera but it gives me the same results.

3)i'm building the game in 320x320 and not 32 x 32 because the tiles often detach from eachother and basically i have some pixel problems. the biggest is pixel deformation. for some reason if i change the camera size my square pixel turn rectangular and stretch. is it right to build it this way or should i build it in 32x32 like it should be?

4) the most important. i often get pixel stretched. no matter what setting i do in the sprite menù like "no compression" and so on, they still stretch. i think it has something to do with the camera. i want to export this game for smartphone and i want it so that whichever size of screen it is played in, everybody sees the game in the same screen height but with different screen width, but in doing so my pixel get stretched. how can i do it like so?

hope you guys can help me with that


p.s. already removed antialiasing, filter mode and compression, i need something else.