½ mile of gravel will be no problem if you have tires you trust. I've done more gravel than that (and "gravel" is being nice — it was not nice tiny pebbles, but more giant sharp rocks, 1-3cm in size) easily even just using Conti GP4KS2s.

I run a size 44 shoe and a size 56 Roubaix and I have plenty of toe overlap, but I only notice this when I'm trying to turn around at 2mph and I've forgotten to move my foot out of the way. It's just like cornering — if you're going to be moving the bars that far to the side, make sure you move your feet out of the way.

That's a SHARP turn if you're moving at any kind of speed.