As I already said, the X-E1 has an older Sony sensor (a variant of the one inside the Nikon D7000) and then Fuji tweaked it a bit. Grain is not an issue on today's APS-C cameras. Not on mirrorless and not on DSLRs.
The image quality, high ISO performance, fastest autofocus and all that stuff...
Imagine I just slapped you in the face, I'm pointing my finger on you and I'm yelling:
STOP READING BULLSHIT ON THE INTERNET!
Don't take this the wrong way, I have been there, I have done all the stupid things. I am just getting angry because I know how dumb I was for caring about all the numbers, reviews, comparisons and so on and I want you to not make the same mistake.
It doesn't matter what camera you buy, it doesn't matter how much money you spend. Every camera has limitations. No camera is perfect. And regardless what camera you buy today, the weakest link for your photography is you. Not the technology. You need a starting point. Buy a camera and use it. Really use it. Every day. Take your camera outside, throw it in manual mode and make good pictures! You, not the camera. You!
I now had time to compare the cheaper 35mm f/2 from Fuji to the 1.4. I have to admit the f/2 is the better lens overall. Optically they are on par and the f/2 is ... well, f/2 instead of f/1.4. But the new lens is quieter, weather resistant and does focus more accurately on my X-Pro2, even in very low or artificial light. If you haven't pulled the trigger so far, you might look for the newer, cheaper f/2.
The bokeh is pretty similar actually. Bokeh describes the quality, the beauty of out of focus stuff. It s not a term for the amount, of how blurred the out of focus stuff is. At f/1.4 the background will be more out of focus than at f/2, but the f/2 image can still look more pleasant.
No, the difference is simply that the 35mm f/1.4 can gather more light. It can open the aperture one stop further.
So, light travels at a fixed speed, right? Think of the aperture like a pipe with water running through at a fixed speed (because speed of light). Lets say 10L pass through the pipe every second. So, a thinner pipe with half that troughput (5L per second) will still get the job done but it will take twice as long, right?
That is the same relation between APERTURE and SHUTTER SPEED. It is exactly like that.
So you open up the aperture to f/1.4 and take a shot with 1s shutter speed. Now you take the same shot with f/2 and 2s shutter speed. And both images will have the same exposure, one will be as bright as the other. Because in the end the same amount of photons ("water") has passed the lens ("pipe") and hit the sensor.
OK, now how important is that one stop more of light? For you right now it is not important enough to care about.
TL:DR Buy the 35mm f/2! Used or if Fuji is running a cashback thing in your region maybe even new.