If you decide to change it, maybe use the black panel at the end for the logo, and put it at the beginning.
I don't think there are any real advantages to switching though... Your comics read well in the single line format.

Odd number of panels, make the last one twice as big? (fill out the space)

Can't say I am much of a fan. To me it looks kind of awkward. I like the older ones personally more; they seem to synch up better.

I think if you have an odd number of panels, you could just put it in the middle at the bottom; that, or you could use both layouts. If it's an odd number, use what you've always used, and if it's an even number, use the new layout.