Your are going for the big bang solution (and getting it).
You system should be treated as at least two, if not three seperate pieces.
The first is your computer. The second is your breakout board and minor electronics (limit switches and other bits and bobs), and finally your power house - the motor drivers.
All three are seperate - electrically - and must not be joined together (with one exception - a single common lead).
Your computer I will leave to you - you seem to know more about them than I do.
I am not a lover of the C10 breakout board - for some reason, all the normal LPT1 inputs and outputs have had their voltages reversed, and it seems to be trying to be all things to all men - but - this board does require a 5 volt power supply. I DO NOT RECOMMEND YOU USE A SUPPLY FROM YOUR COMPUTER. If you do, any wiring fault on the board can send power back to your computer and blow it. Use a seperate small 5 volt power suppy.
You must the read the C10 documentation very carefully to get the various jumpers in the correct positions. On LPT1 (as you probably know) you can only have pins 2 - 9 as outputs, 1,14,16 and 17 as outputs and pins 10,11,12,13 asnd 15 as inputs. Make sure the jumpers for these are correct.
The axis are normally run from pins 2,3 4,5 6,7 and 8.9 - the C10 has these arranged with a common wire between then- and the voltage on this common wire can be altered from 0v to +5v. This depends on your driver cards.
I would jumper the "enable"pin to the 5 volt supply - so that your axis are turned on. You can alter it later if you wish.
You can now connect your computer to your Bob (you do not need your machine connected) and check that you are getting signals too and from. You can certainly see the "dir" pins change voltage. I tend to check mine with an M3 command (M5 to turn off) and alter the pin configuration to test all the output pins. The input pins you can allocate on the Ports and Pins page, and test by putting +5 or 0v in the appropriate pin and checking the diagnostics page.
You driver cards that run your motors are completely seperate. They require whatever voltage you are using, and can be wired seperately. You can turn the power to them "on" and they should "grab" the position and stay there. There is nothing else to say other than they handle quite a lot of power, comparatively speaking, and you should be careful there are no stray "hairs" from you connections making other unwanted connections.
The only connection between your Bob board and your drivers should be a step wire, a direction wire and a common wire to the input side of the driver card. There should be no high voltage connection between the two boards. The 5 volt supply for the BOB should not be derived from the power supply to the steppers.
I use Gecko drives, so they require step,dir and a 5 volt common - switch your Bob. If your drives require step,dir, and a 0v common switch your Bob.
Again, If you have derived your 5 volts from somewhere, then this common switching could easily short your supply. Use a seperate 5 volt power system for your Bob
I think reading between the lines, your problem was the power supply to the Bob - especially with C10 documentation saying that you can use computer power supply or USB. You have then also probably used this supply to switch enable switchs of the motor driver cards, as well as the axis enables on the Bob.
Keep each part seperate - and only join the minimum number of wires - e.g printer cable between computer and Bob, step,dir and common between Bob and driver - and you should prevent the pyrotechnics