-Poser allows for multiple runtimes, so you can split stuff up and get a faster load.
-You can put an IK_OFF script on one of the script menu bittons
-Move objets with the parameter dials , its much easier than trying to drag in the preview window.
-I run Poser 7 in fast mode with texture display and its fine for several figures and scenery. If it starts to slow I go to smooth shaded.
-Use the pulldowns to select figure or bodypart/prop/light etc.

Poser crashing is bad , and has been a problem for a long while. Save often .
If crashing is getting too persistant try deleting the libraryprefs.xml and the UI interface.xml files and let Poser recreate them. You will need to add external runtimes again.   

These are just points I have learned over several years with Poser.

And yes it is a hobby application. All the content is incredibly cheap compared to what I can buy for aLightwave or 3dsmax.  YAY poser.