Wattle (or should that be "Bloke"?
),
A couple of comments -- first, adding the PC during the make is standard practice for many of us. Second, it sounds like you experienced slip skin in addition to tearing; I'm not absolutely sure about this, but given how early it is in the process I'd say the chances of it all growing back together are good. However, I'd recommend moving your cheese to a colder fridge to finish ripening -- this will slow it down and allow it to even out more; it will also intensify the flavor. Either way, you need to keep the humidity high; the easiest way to do this is to wrap in the cheese paper, or you can use a ripening box.
One final thought: I'd encourage you to move away from the beet root cans as soon as possible. It looks like they are standard, lined, "tin" cans (which are, I think, actually steel). The problem is that cheese is a high-acid food, and anywhere that the lining is absent -- at the ends, or a scratch in the lining -- the acid will react with the steel, leading to off-flavors in the cheese. Also, it looks like these have no drainage holes in the sides. I don't honestly know how important it is to have them, since it can drain through the bamboo mat at the bottom, and clearly it did that for you, but generally a "real" mold will have the drainage. Since there is no pressing involved in this make, you can use even a relatively flimsy container as your mold, punching holes through with an ice pick as Ann has said. For example, I've used re-purposed Cool Whip containers. (Not sure if you have that product by that name in Au?)
With all that said ... who cares if you did everything "by the book"; the only thing that matters is that you like the final result! Looking forward to the taste test ...
On edit: by the way, coulommier is pretty much the same thing as brie or camembert, from what I can tell -- it comes from a different region in France, and is made with a slightly different shape, but the basic idea is the same. Ripening paper is a huge convenience to me -- it allows me to handle the cheese more easily (ie, when flipping it) and not to have to worry about the humidity level, especially when I move to the cold (and very dry) fridge -- the cheese forms its own micro-climate inside the paper. But you can achieve just as good results using a ripening box if you don't have sufficient humidity in your ripening area. Do a search on "malembert" - Mal (OzzieCheese) is the acknowledged master of this make; his notes have been very helpful to me.