Does bullet chess promote bad habits

My experience has been that I improve when I slow down and train myself to look deeper and deeper into positions.

And that playing a lot of faster time controls can encourage superficial thinking. 

I'm actually on a nothing-but-standard-and-correspondence diet at the moment to see what happens. 

I feel mixing it up doesnt hurt. Bullet to me (as a poor bullet player) is about playing as many decent moves as possible in a short amount of time. If you can keep yourself out of trouble and play fast you generally win. So in the sense of being able to identify a not terrible move almost instantly is a great thing to have. The problem is you never think deeply. So yeah, as a bit of fun why not? it probably won't affect your rating much and might help solidify your openings.