5i25 + 7i76: Axis mixed-up and movement only in one direction

Hi there, im in the middle of setting up my XYYZ gantry-style router using a setup based on a 5i25 and a 7i76 as a breakout board. i'm running four Nema36 closed loop steppers (www.wantmotor.com/closed-loop-stepper-mo...p-stepper-motor.html) with chinese drivers (manufacturers site is quite useless; see manual here: www.hobbytronics.co.za/Content/external/...S880%20programme.pdf). i guess thats about as generic a setup as can be, right?  

Well ive been struggling since the beginning, first issue was that i mis-wired the encoder inputs from the steppers, luckily GND was in the correct spot, but i figured that the driver got a signal on one of the encoder A/B-pins because the motors were shaking as hell. got that resolved, yay! 

Then next issue i could clear was that i messed up something with the power supply, i feed the four switching supplies for the steppers with 230V, also one 24V supply for Vfield on TB1. Regarding the steppers+drivers+7i76, i double and triple checkd that everything's wired correctly then, but the steppers just didnt react at all when i fed them some pulses via StepConf. I then measured that on the 5V-pins of Step/Dir[0-4] on TB[3-4] there was only a tiny voltage, something like 0.1-ish, far from the supposed 5V. Those 5V logic voltage come from the 5i25, which has a seperate power connection btw. Also i noticed that even when the power to my cabinet was cut, the LED for indicating 24V from Vfield was periodically flashing. Oh well, i then re-did the wiring, bypassing the contactor which i thought was a good idea to dis-/connect the mains power from/to the cabinet. I guess the problem was that i used the Neutral line to break the power connection. Anyway, after re-doing the 230V-connections and properly connecting all neutral and earth wires, the 5V LED on the 7i76 now lights up an the steppers finally *ARE* moving -- great success!

TL;DR - the (two) problems i am now facing is
a) somehow the mapping between my phyiscal drivers and the step/dir-ports on the mesa is messed up. clicking through the pncconf-wizard, i assigned STEP/DIR0 -> X-Stepper, 1->Y0, 2->Z; nothing fancy, for now i wanted to get the motors up and running and worry about dual-Y-axis later. now no matter which axis i select (X, Y or even Z, respectively STEP/DIR0,1,2) - its always the X-axis that moves!
b) to make matters worse, that X-axis is only capable of moving in the same direction  

bonus infos
- on point a) when i enable tandem Y-axis, then STEP/DIR 0+2 are moving together; so i guess the hardware step-generators (at least 2 of them) are okay? 
- i found the following thread -> forum.linuxcnc.org/27-driver-boards/4794...moving-one-direction which mentions that the 5i25 might be bad? i wouldnt be surprised if i fried something given my amateurish handling of the power delivery; but at no time i tripped any breakers or seen any other indication of errors (besides the erratic behaviour of the system altogether).

i am currently at work so i only have access to the machine's HAL + ini files and cannot give detailed info on which software versions are involved. i will attach that info ASAP; but given the fact that i only used tools that come with the stable version of the linuxcnc-iso, i would like to exclude sw-bugs; and from my point of view, i think my setup all-in-all seems fairly standard... 

thanks a lot for your attention!