building a rack, wiring flexwatt in parallel

[SquamishSerpents]

just have a few questions about the wiring of our new rack, i'm a very visual person, so i thought i'd draw a little diagram:



so basically what we'll have is 3 racks, that hold (3 x 3) 9 tubs each. my biggest concern: will splitting up and then plugging back into the next 3 x 3 rack be a problem? will everything heat consistently? we are using all 11" flexwatt, the whole way through. i'm just concerned that maybe in parallel the heat won't distribute properly?

i know it'll be a bit warmer on the top tubs, as heat rises, but we just really don't want each (all 12) rows to have a plug sticking out.

also, should one of the strips of flexwatt fail, what would happen to the others? would they just pick up the slack and the herpstat keep the temp at 85 on every other row, regardless of one being out? for now i just have exoterra digital probe thermometers for the temps, but i plan on getting a tempgun within the next few days.

thanks for any help, i'm no electrician!