Hi there,
The website is about to get a major rework, it'll be clearer on the new one
For now: with the basic version you get everything except declipper + natural dynamics, delossifier and all FM-related stuff (which you don't need obviously if you're not doing FM broadcasts). You do however get all the other stuff, like AGC, equalizer, stereo enhancement, multiband, etc. The declipper can restore clipped audio really well, so I can recommend getting that one with the basic license (you get a discount if you buy them in one license), but it's not required for basic operation.
You can change the bands in every version. However, by default Stereo Tool runs in "Basic" operation mode, which hides most of the settings and just sets them to sensible defaults (otherwise the number of settings would be overwhelming to new users). Somewhere under the 'Configuration' tab you can change the level to e.g. Advanced or Expert, then you will be able to change the bands.