Is there a risk of bottling a stuck beer?

Let's say I use an English ale yeast on a 1.053 beer and it craps out at 1.021. So we can estimate it's probably .005 from its finishing gravity. But I like the flavor, or I'm in a hurry, or I don't want to go to the trouble of rousing the yeast or repitching. What happens if I bottle?

Is there a chance that adding corn sugar will rouse the yeast and I end up with more carbonation/bottle bombs?

Yes there is a chance. I assumed one of mine was done, and started bottling before checking the hydro, then carried oon anyway. I ended up with bombs.

Rouse it, don't rush it. Stir gently with a sanitized spoon, and warm it up a little.