Just had a quick listen:
1. If you use reverb (or delay) on bass frequencies they get washed out, meaning they will loose bass and punch. If you don't want to change your reverb (and I am not suggesting you have to) I suggest you use your reverb filter (don't know the real name), I don't know Cubase or studio one well, but normally there is a possibility to limit the bandwidth of your reverb, just like you can limit it to 12kHz to make it less obvious. In this case I would use the filter to remove the low end of the reverb, meaning there is only reverb on the mids and the highs.
2. Mixing a vocal on a track is not easy (so normally you would start with the vocal in the mix). The problem here is that there is no room for the vocal to fit in. So just make place for the vocal in the backing track. I would start to get the vocal how I would want it to sound, and then remove the most important frequenties of that vocal in the backing track (that would be something between 1,5 and 4 kHz). And you will be surprised how little bass a vocal needs once all is balanced.
3. Reverb: while panning shifts you from left to right, reverb will shift you from front to back (I am quoting Dave Pensado here). Meaning: the more reverb, the further away it sounds. For example: if you keep the vocal dry and the snare wet, the snare will be behind the vocal. Do it the other way round and the vocal will sit behind the snare. Here the vocal is much drier than the music so it sounds disconnected as someone said.
4. Looking at normal meters to guess how loud something is, is silly. The human hearing is much more sensible to the average level than to peak levels. If you want to do that with one compressor, it will have to work too hard. So using multiple busses with each a little compression on them will be more natural (I am not saying better..)
Hope this helps, and if it doesn't help, just ignore it. So many people can tell you what to and how to but you have to find the way for yourself (I am sounding like Buddha now?), everybody hears things different, so what will work for someone else, won't always work for you. Just like learning an instrument.