just reminds me of this:
https://www.youtube.com/watch?v=Gzv9g_NOE6I
Depending on how out of control the delays get, i would maybe think of adding a limiter to the end of them (next to the tuner) so that it can stop them escalating to too much of a volume.
If those are the right combination of preamps you need to get the tone(s) you want, and you can get them from point A>B and back again okay, then id say dont worry about that.
As for pedal order, i dont think that there would be many presidents for gigged boards with that many delays on them. Id just suggest just playing about with order, just to see what happens. Maybe adding a pedal in between some of the delays, maybe just to see what happens. You can always put them back to this same order after.
Pedal order is one of those things, if its not broke, play about with it anyway. you might find something better ^_^.