Hi Hunter - in MoI you would draw some curves, use Construct/Extrude to create solids, and do booleans to do that kind of stuff.

Use Boolean Difference to cut one solid with another.

Use Boolean Union to fuse 2 solids together like if you want to make a protrusion.

If you want to do an "inference" to align things, drag out a construction line for that - hold down the mouse button and drag away while in a drawing command, rather than the normal click and release which places a point.

Use Construct / Offset if you want to produce an offset curve from a selection of edges or curves.

Those are the tools that you would use in MoI to produce the same result as you are showing.

I'll see if I can make a few additional illustrations to show this.

But you'll definitely want to check out the main tutorials here which give a good introduction to the overall workflow and many basic functions such as booleans:
http://moi3d.com/1.0/docs/tutorials.htm

- Michael