I'd recommend keeping your arms out during the standup portion. I notice wrestlers and the like tend to use "hooks", and grab a lot around the head/neck/shoulders. It's kind of hard doing aikido when some guy's pinning your head down with a clinch. If you make sure that they have to go through your arms to get to your body, at least it increases the chances of something happening at more aikido-ish range.
not sure if that is such a great idea Paul. You'd be susceptible to things like arm drags and maybe even flying armbars...