I missed question 2.

Here's the thing. It'd be great if the $500 to $5000 you spend on a 3D app could do everything and do it well but the reality of life is that this won't be the case....pretty much ever. The reason plug-ins exist, wether it is for 2D or 3D is to enhance, replace or provide features that are lacking or missing in the core application. 3DStudio Max initially only provided a scanline render engine, so for raytracing, you had to look elsewhere or get a plugin. I don't know if that's still the case but that hasn't stopped plug-in designers trying to come up with a better render engine than the one found in a core application. So yes, ideally, it'd be great if Max or Maya or XSI or LightWave or Truespace or Cinema could do it all straight out of the box (and you'll find in most cases they can...just not as easy) but for the 99.8% of us who don't get to experience the ideal, these plug-ins are essential to getting the work you need done, done. The same goes for Photoshop and its ilk.

As for the rest, both Cornelp and I have given the only unbiased answer you can really get from anyone and that's to try it yourself.