more likely if you are working adult now, you have spare money, you can spend your money like a boss, then we can poison you all we like here 

but if you are student, go back home and study your homework lol  (unless you are serious and want to use that for part time job)

also image quality i think is pretty much affected by Lens first; second one will up to body you used (unless your body is obsolete tech)

also another option is you get D7000 series which is higher rank in DX (or D500)  without sacrifice your DX lenses

There is definitely a huge difference in the focusing speed and dynamic range. Since you are not shooting sports, you don't really have to bother about focusing speed right? 

Bokeh wise, it is the lens that matters. Get a 85mm F1.8 for the bokehlicioussss   

I bought D750 to shoot for wedding/events. Both is capable of shooting video at 1080p with 60fps and capable of shooting photos at 24MP. But sometimes i prefer to use D5300 since it is so much lighter and it is really tiring to hold a FF camera for video.

I still use D5300 a lot (it is so much lighter and smaller) for casual portraits and landscape.

But when it comes to professional service, people tend to judge a lot. A professional holding a D5300 doesn't look more professional than a noob holding D750. 

This is also another reason why I only use D750 during actual day wedding and also corporate event shoots.

That's why I recommend you to go for full frame when you are shooting wedding often. Otherwise, D5300 should suffice. 

Actually I once consider D800. 32MP, 1/8000 SS. Super impressive. 

But too bad, it shoots max at 1080p with 50 fps. And more expensive than D750 

So i got D750 in the end 

I use DX lens on FX body shoot at the full area.

How many of you would believe me if I say this was taken with DX lens on FX body? http://myfigurecollection.net/picture/1621896

I took the photo with 40mm DX Micro lens, after that crop the way I like.