Did I read correctly that it only needs 2 PCI-e cables connected to run as normal (not overclocked)?
Correct. 2 for regular, 4 for OC'ing.
What I do not understand is this sentence: "Dont parallel connected different DC input from different PSU into the same Hashing board." So does this mean you need two PSU if you're overclocking?
I understand they mean dont use 2 PSU for same hashing board. Anyways, with 1 PSU u can connect 4 PCI-e so no problem
yeah this is most likely exactly what they mean.
but with 2 psu's each one doing one board each even thou it seems okay I will let some one else do it first.