multiple remotes & power save mode

i’m playing around with a little hobby project here at home and have a few questions regarding power saving mode configuration.

firmware = 10E6
1 coordinator
6 series I remotes
one wire sensor on each pin DIO0

  1. would one set sleep mode values the same on each remote or stagger them a bit?

  2. should ST param be the same on the coordinator as remotes?

  3. should coordinator SP=0 versus matching the SP value on remotes? guess this depends on answer to Q1 …

  4. for such a small scale would it be better to get Series 2 Pro’s with ZB firmware?