I'm using SE and don't know about VST 5, so maybe they are different. If you want to have one signal completely dry and one signal processed, the only way I know to do it is to clone the track and apply effects to one of them.
The grouped tracks are for adding the same eq/effects/automation to multiple tracks. It can be useful, but I don't use it much.
The VST effect sends (look in your devices menu for 'VST Send Effects' or something similar) allow you to send part or all of the signal through the effects bus (very similar to an effects loop on a mixer). Therefore you retain as much of the dry signal as you want and can add as much effect as you want. Generally speaking, send effects are 'post fader,' not 'pre.' Also, you don't usually want to have the send amount 'right up.' Only send as much as you need. On reverbs, for example, I typically send ~5-20% of the signal through the effect. The remainder of the signal is unprocessed.
Here's a screenshot of how a send effect appears in SE: