Cool.
Not exactly on topic, but may I suggest you try a flash diffuser (e.g., Lumiquest ProMax 80/20 is what I use), and possibly a bit lower ISO. Some of your flash lighting looks pretty harsh and the backgrounds are quite bright.
Some time ago I shot a reunion in a venue that looked a lot like yours (I had a high white ceiling to work with) and with a single 550EX and ISO 400 was able to get pretty nice mix of overhead lighting with fill that was both soft and set the subjects off from the background a bit. For example:
-Noel