Well I was asking the same thing a few months ago.
I started out with all those same devices on IRQ 11th as well. I decided to put all on seperate IRQs, sound IRQ 5, video IRQ 10, ethernet IRQ 11. I haven't noticed any difference from the original configuration.
So this is my opinion.
Unless your having an IRQ conflict problem or something I wouldn't worry about it.
Assigning seperate IRQ's would just be like organizing.
It will just help insure that things run smooth, but you most likely won't notice any difference.
So it's up to you.
Sometimes sound cards and vid cards don't work as well as they should when they share the same IRQ.
If anything I would change it so the vid card has it's own IRQ.