Many things in higher editions can be faked with creative thinking. I have Commercial edition and with it, mirrors are possible (to a limited extent), an unlimited number of physics objects (just write your own physics engine, possible even with standard), LOD (my method is much better than the engine's very restricted system - so much flexibility, the slight speed difference (sometimes slower, sometimes faster) makes it worth using more than the engine's LOD system). Heh, I even created a fully working 2D game that's on the verge of release for sale where I had to script everything (even without the templates), including the physics, movement, menus, and pretty much everything else. The highest edition you really need for anything is Commercial. Extra can be good in other cases as well. I suggest at least extra edition for starting out. If you don't like it, you can almost always sell your copy, provided you contact Conitec first.
For the file packer, get Molebox. Although not free, it compresses and encrypts your game files into a single EXE and is otherwise very useful as it seems very secure. You'll only need this if you intend on releasing your game and only when close to doing so. Start with Extra or Commercial and build your game. It takes a lot of time to make all those models and levels needed. Also, may I suggest looking into the Benchmark Tester, a tool I made (on the downloads page

) that analyzes how many polygons and vertices per second your computer can render to help optimize your model-only levels? Model-only levels can be 50 times faster than BSP (block) levels along with tons of other advantages.
I also suggest downloading the trial and get a basic understanding of the program. The trial is free and lasts 30 days. Good luck and enjoy making your own games (or 3D programs in general, such as interactive 3D movies).