The floaties are normal. They are just a combination of yeast and hops and whatever else was put in there.
I, personally, don't think the 6 gallon carboy will be an issue. I have done that with a bunch of batches with no concerns. Other people on here may argue otherwise. A lot of people on here don't even secondary at all, and just leave it in the primary for an extra couple weeks/months. So by that, a 5 gallon batch in a 7 gallon or so primary fermenter would have a lot of headspace, but maybe I'm not seeing an important difference....
If I were to keep it in secondary for a long time (several months, like a wine/mead/cider) then I would be a little more worried about the amount headspace.
EDIT forgot some stuff: Did you end up racking to secondary? Or were you waiting on a response from here first? I would do as jourelemode said and leave it in the primary a little longer, it wont hurt it. Just remember to check several gravity readings to be sure its done fermenting.
Also, 73 is a little higher than what I try to shoot for. Usually 65-70.