I figure, but could be wrong, that you would get all the molds they used in the bought cam by using the rind. So, provided they used geo of course, you would end up with both developing. I wouldn't think the geo would die off completely, but I could be wrong. As for the warm water, I tend to go with something in a similar temperature range as the milk you'll be adding it to. In part because it helps soften up the cheese and rind that you're using and should make it break up into finer bits. I don't think you want to add any "chunky bits" to your milk, and the cloudy water should have enough in it to do the trick.
The cam's I made were the first cheeses I made at home, so I wouldn't have recognized what was growing at the time (and it was last year, so I don't recall now). What I do know is that I didn't get slip skin, and the cheese turned out quite nice. It did go very bitter after extended aging in a regular fridge, but I think I over renneted it and attributed it to that.