Where is the fountain of knowledge for learning about CNC setups / understanding them

[JAZZCNC]

Ok well first don't spend any money on anything because you still don't know what the problem is. Could be anything and throwing money at it without knowing what problem is foolish and sure way to waste money.

The steppers you have will be fine so don't worry about those. Steppers are simple things, they just work or they don't. Provided they are sized correctly for the machine, which these are you won't have any issues with them.
Also just because other folks have had cable issues doesn't mean this is your problem so again leave well alone until you know they are the problem.
Grease doesn't need to be anything special, just normal lithium grease will be fine. However don't go greasing anything yet let us get it working correctly first.

So put up the video and let's see what it's doing.

What you can do thou is going over the machine top to bottom checking no loose bolts or slop in bearings etc. Pay attention to the connection of steppers to ball screws. Check ballscrew end fixing that it's not got any axial movement. Also check Ballnut mountings are tight.

If nothing appears to lose or wrong the next thing you can do is check for any Axis binding. The way to do this disconnects the steppers from ball screws and push each axis thru it's full travel length. They should move quite easily with no binding or tight spots.
Don't be surprised if they don't glide like as if in thin air, this is quite normal and something people often misunderstand.

Only after you know the mechanical is ok should start looking at the electrical. Even then provided nothing is broken you shouldn't need to replace anything just to get motion.
Yes if you want to improve performance then will most likely need to replace some components but should still be able to get good smooth motion using the parallel port and what you have.

So Hold off throwing money at it just yet.

Oh and that isn't UC100 so leave well alone.