Manually installing becomes a fairly quick task once your momentum is built up :)

Really, I have never installed via an installer or directly unzipped into the Runtime "Unless" it is a DAZ product. 

Opening multiple windows of the main drive and simply moving content from one window to the other is pretty quick IMO.

Now may be a good time to re evaluate the runtime "Bloat Factor" and only load the content you actually use :)

As for Poser operation a PPC Based Poser 7 is just plain Pokey, Stable but pokey.

Poser 8 on a PPC is MUCH faster than 7 in all respects.

I run on a G4 PPC " Door Stop" as well as on a iMac (Intel) no problems on either machine.

Welcome to the Mac "Cult " Bwahahaha ;)