I am with Richard on this one - that you CAN NOT relaunch your kite in really light wind, especially not in deep water drifting.
Even if too light to relaunch, and too light to "ride" - you are still able to bodydrag to your board though (here I am with JGTR).
But there will be situations in light wind, where your kite goes down, and you are not able to relaunch.
And so what ?
This only happens close to shore, right ? As why would one ever ride out far from the shore, in too light wind to be able to relaunch ??? (unless on purpose and knowing the risks, but that is another issue)
The other thing that struck me when just reading this thread, was the always wrong interpretion that "strong currents" can be difficult when bodydragging
Current DOES NOT make it easier nor more difficult to get your board, as both you and your board are in the current
I dont know why it is so difficult to understand, but bottom line is, that current does not affect how easy it is to bodydrag to your board
It only affect what kite or boardsize you need of course, to get planing and to hold ground, but that is a different thing.
Regarding the "head injury" - of course it is "the ground" that is the major risk in kitesurfing.
Most start and land on land, and most ride in "not offshore" conditions, so no matter what, if something goes wrong - you'll hit something on land most likely
And the leash and board striking, is another risk that exists too, true - so no leash please