Sure. But it's unlikely to be useful at all. Most probable is that an environment that's good for some won't be good for the others - if a compost bin, the regular nightcrawlers etc won't find it hospitable.

Yes, you can mix red wigglers with euros... this much I do know from experience. I have several bins of mixed red wigglers and euro night crawlers set up for over a year and half now. The original intention was to populate a deeper style bin more completely... my typical bedding depth is 12-16" in depth with the euros tending to work deeper than the more surface oriented red wigglers. The two seem to coexist quite well, even complimenting the others preferences and both types appear quite healthy and have been multiplying enough so I've had to split up the bins several times already. So far this arrangement seems to be working out as envisioned... only more time will tell if one eventually dominates over the other in terms of population. I also have African night crawlers in a couple of other deep bins but all by themselves and these guys will go deep and are voracious eaters when temperature are warm enough... however I've no plans to ever put them in a mixed bin because their temperature requirements and eating habits are so different from the red wigglers and euros, it just wouldn't be a good match.