ViaCAD does have a nudge feature to move objects around with the keyboard arrow keys.

To set this up you will need to go into File/preferences and under the general tab you will see a value box next to the words "arrow key nudge distance". If this value is set to 0.0 the arrow keys will nudge the whole screen. If however you set this to any other value, a selected object will be nudged that distance in your set units.

To constrain to a certain axis/plane when moving your mouse to translate or extrude hold down the letter representing the desired axis. In other words if you want to stick to the y axis hold down the y when moving. This constrain works with any tool and with any function.

It can be a bit inconsistent. I try to have the constraint key pressed before I click on an element. One other thing to be aware of, the Z axis is up in the perspective view and in planar views, Y is up.