Firewire is DESIGNED to daisy-chain devices.
There's more than enough bandwidth in Firewire to stream more than 100 tracks with half the bandwidth left over for other things. Like multiple HDTV video streams (I edit video too and it's MUCH more bandwidth-intensive than audio.)
I'm running a Glyph firewire drive daisy-chained to my 828mkII with zero problems. Motu guarantees that I can daisy-chain >THREE< interfaces together for over 60 simultaneous ins and outs.
....that's the whole reason for Firewire.