"...are the large trailing arm bushes tapered?"

In a manner of speaking. One end of the bushing (the outer metal sleeve) is tapered or rounded over, sort of like a "bull nose" end. The other end is very slightly flared, but this is hard to see. This flare, or expanded section, causes an interference fit as the bushing seats the last 1/4".

"...which way do they go?"

The bushing is installed from the (differential) center oriented toward the wheels (inside toward the outside). Obviously, the old bushing is extracted by pulling it from the outer (wheel) end toward the center of the car.

Also, the bushing has an "up" and "down" as indicated by an arrow molded into the rubber.

When removing and installing, it is important to support the two flanges (which are welded to 'n part of the axle tube) so they don't bend and "cinch" the bushing. Part of the tool kit is a spacer for just this.

"...how easy it seems to split the atom..."

Almost as easy as goin' fission....

"...build large building..."

But this creates 'fusion.....