TD - my main focus is on Race to the Stones at the moment, and a spring marathon doesn't really fit with my plan. But I'll be going over to support. That'll be 3 years supporting, 5 years running, and 2008 when I happened to be in Paris on marathon weekend, went to watch, and thought 'that looks like fun' .
Amandalou - if you come over from Oz you don't HAVE to marry someone from the thread, but you wouldn't be the first...
reflektin - missing one long run won't ruin your whole plan, but don't jump up too far on your long run distance when you get back. And if you can get out for a run or two while you're on holiday just to keep the legs turning over, that will help too.
Lowrez - funny you should mention that, Bruce did jog round in a relatively leisurely 20:48 in 2014 .
Another single female traveller here. What everyone else said. There's a big group of people from here and plenty of events, and you'll spot the Comrades t-shirts from the airport onwards. You needn't go anywhere on your own if you don't want to, and taxis are cheap and fine. Just bear in mind what Dannir said, whether you're male or female - keep your eyes open, don't wave any expensive-looking accessories around and be generally sensible.