First off, here is a thread that explains all nodes:

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2722867

All clothing for V4 and hairs SHOULD fit in 0 pose with NO poke thru. If your getting poke thru on knees and elbows, I would choose that body part of the clothing and look for either fix morphs or adjustment morphs. Quality clothing either has jcm's fixing these issues or should have adjustment dials/morphs. If your clothing isn't fitting and you need to scale body part dials, either your not using the provided morphs right OR that clothing wasn't created for V4. Be sure to read all readme's on clothing as well.

V3 and v4's bodies are completely different so you won't get clothing to fit between the 2 of them unless you buy a program that transfers clothing from one figure to another or a magnet set to do so, which will require a lot LOT of adjusting. These are 2 completely different figures, so you will have the adjusting.

If you've happened to browse through the galleries here, you will see v4 CAN be rendered nicely time and time again....I would suggest better lighting, render settings - im not doubting your ability to render in poser, but if the results aren't what you hoped for, time to try something different.

Maps for v4 cannot be applied to v3 as the mapping isn't the same. I agree freja and Adiene's character skins are amazing as well !

Wishing you the best of luck!

Ever stop to think, and forget to start again?