@PsionsThis is what you can access from the UI side of the game:
Among others, this includes:
- GetIdleEngineers()
Which is also used to make a button on the right side of the screen on which you can click to move to some idle engineer.
- UISelectionByCategory(expression, addToCurSel, inViewFrustum, nearestToMouse, mustBeIdle)
Which is a bit on the edge of things that is possible but never the less it can only select your own units. The 'snipe warning system' you mention is just not possible through a UI mod.
What a UI mod does is interpreting the data from the simulation. In turn, the UI side can send some commands back (such as 'Pause' and 'Stop', which are the only commands that work) or display information in some UI (which is the UI that you are looking at)
Comparing this to an aim bot is a bit of a stretch, but I do understand some UI mods can provide significant advantages, such as ATP.