AutoCad :: Drawing Isometric In 2D

I'm currently taking an CAD program and I'm having trouble drawing a few objects in isometric perspective. These objects must unfortunately be drawn in 2D. I've drawn the orthographic perspectives for each object based on the dimensioning given however I'm unsure how to proceed on certain portions of the drawing. This is all homework and I doubt using any customization is allowed.

The first image is a top view of a fixture. I'm having trouble with the central portion which I draw by first constructing the vertical arm then using the array command.

Is there some way to create an array of this object that respects the isoplane that I drew my isocircles in?

If not, I'm able to look at the original using the VPOINT from the 1,-1,1 point and get the perspective that I want. Is there a way to use the UCS and trace over the orthographic perspective then take that traced image back to the world X-Y plane? I've tried this before but once I get it back it simply looks like the orthographic perspective.

The following drawing I'm simply having trouble drawing one particular curve which the green arrow points to. The drawing is of two perpendicular intersecting cylinders one having a slightly smaller radius then the other and the curve in question represents the edge formed by the intersection. The research I've done indicates that it's an ellipse however I'm unsure how to draw it correctly and the one I put in is simply an estimate. How can I construct the correct curve? Even if I could change viewpoints I'm not sure I could find a way to trace this one.

How to draw 2D isometric images from orthographic projections in AutoCAD as it seems many of the sites I find are either trivial or focus on drawing by hand.