Q:
What is the purpose of Bone?
A: Bones are used for Animation purposes, you will find in the 3D Studio Max Tutorial Help a section dedicated to explaining how to Rig a Model for Animating it. It covers how to create mostly the bones so they work like a Humanoid, however there are also Enveloping tutorials that show you how to assign the Vertices of your Mesh to the Bones.
Q:
How does UV Mapping work in 3D Studio Max?
A: Annoyingly this is a difficult question to answer, but it is quite simple once you understand.
The easiest way to Skin your models, is to select the model then in the Modifiers try using the Sphere / Planer / Box Mapping, then UVW Editing. The Editor I believe again is covered or overviewed in the Tutorial help.. Alot of it works similar to the Mesh Editing, only your doing it in a 2D Area rather than 3D.
Q:
What are the purpose of MaxScripts?
A: Advanced modellers will often find that while the tools do close to what they want, they wish to have a tool created for a specific task they do often. MaxScript enables you to create specific tools for your needs, as it acts as a Mini-Language for the Max program.. it means just about everything Max can do through C++ Plug-ins is also possible through Scripting.
Not something I've ever personally got the hang of to be honest, reminded me too much of Visual Basic.. made me want to throw up using it
Q:
What are NURBS & Particles used for?
A: CGI artwork, they generally have no place in game modelling.
NURBS can be used to smooth out a surface, however the problem with them is you need to practise in order to use them effectively. You'll find they'll only come in useful with static mesh and world mesh, with areas that need the hint of smoothing just to take away a very abrupt edge. This works better than usualy Sub-Division as it doesn't just add faces but actually curves the surfaces.
Useful for Organic work.
Q:
What is a Dummy Object used for?
A: Just about anything you don't need to export. You can use it as grab-box for a Rigged Skeleton, or you can use it as a marker for something, etc.. As they're not exported or rendered, they can act as being the scene 'X' Objects, and used for whatever you see fit that a standard object would be pointless for.
Q:
What is Reactor used for?
A: Reactor gets it's name from what it does.. it is a Dynamics & Physics System, that allows your objects to react to each other as if they were in a realistic environment of your creation.
Q:
Does someone need to know thier modelling package inside out?
A: No, however a firm grasp of the concepts and ideals behind techniques is required to make a sound choice. From your questions, I would actually have to questions your understanding of the application to the level where it would be worth spending the money.
Personally I advice people to use the Free versions prior to purchase, unless they need it for Education purposes.