A long time ago I decided that I'd prefer to be embarrassed by doing a 6-point turn rather than by dropping it trying a U-turn (or fewer than 6 points)*. Particularly if there's no-one around to help pick the heavy lump up. And, yes, even if there's no-one around, I feel embarrassed.
So far, my riding companions haven't commented (at least within my earshot), even though most of them are far more skilled at tight turns than I am.
As for front or rear braking, it's more difficult to brake gently to a stop with the front brake. I think it's that relatively sudden stop that gives you less time to reduce the lean. But of course your foot wants to be hovering near the ground rather than over the rear brake lever.
My advice would be never to hurry, and always get the steering straight as you come to rest (even if it adds a couple more points to your turn!). Straight steering means the bike is better balanced for the stop, and, even if the surface is slippery, using the front brake won't inevitably lead to a drop. Though avoid the front brake if you can!
* This is, of course, is the one area where my YCC-S bike is at a disadvantage. Even my Gen 4, though better than the Gen 2, still makes tight turns more difficult.
I told her "Not while I can still get a leg over one."
