Will, I have what I think is the 'standard' VS front swaybar installation. Here's how it was installed when I got the car. With stock (non-lowered) ride height, I too have about five inches of ground clearance, which seems to be enough - I don't think I've ever hit anything with the swaybar.
But, as has been pointed out, things don't stay the way they are in the photo once you're moving down the road. The sway bar swings up as you hit bumps. Way up.
When I first got the car, the front suspension seemed very rough and I got a lot of 'clunking' going over bumps. It turns out the sway bar was hitting the U-bolt that holds the bumper bracket. I had only about 3/4 inch travel before the bar hit the bolt.
So, we trimmed the bolt back and this made a huge difference. But, now I see that the bar (even though it's mounted in the inverted position) is still hitting the bracket itself on big bumps. This doesn't happen much, but it's something that needs fixing. And just when I thought I'd never have to do anything more to this car.
You can see from this why VS has the sterling reputation it does for thoroughly sorting every last detail before any car leaves the works. And why it's a good idea that any new car be inspected carefully by an experienced VW dude.
One last note about clearance. I too had clearance issues with the sump. Some of our brothers with A-1 exhausts have pipes that hang lower than the sump and that is in some ways a good thing. With the Vintage Speed exhaust, the sump is the first thing to hit. I know this to be true, but I'd rather not explain exactly how I know. I also know that the drain pan bolts are the first things to hit and that they're not nearly as durable as you might suspect. And finally, I know that banging the pipes causes less damage than banging the sump.
I eventually had the rear torsion bars adjusted to raise the ride height a little. I'm not crazy about how this affects stance, but I now have comfortable clearance under the sump. It's now at six inches, so I should, in theory, hit the front sway bar before the sump. And VS has proven over the years that the front swaybar can stand up to quite a lot of contact with things that go bump.