It's a heck of a lot bigger than a bag of holding, it has a wide mouthed opening for inserting large things (like boats), and it weighs as much as a piece of cloth (which is to say, pretty much 0).With the bags, you have to worry about sharp things piercing them, because they are still just bags, the only difference is, they're bigger on the inside than on the outside. Portable holes are effectively a mini-dimension all their own, so no worries about poking through, just like you don't have to worry about poking through this dimension into another with the knife in your pocket.
The drawback to the hole is that you have to lay it down on a flat surface to open it, can't just reach in and grab stuff when it's in your backpack.
In answer to the original three questions -
1.) no, it is not a cartoon hole. It doesn't pass through things. When you lay it on a surface, a portal to another dimension (albeit a very small dimension) is opened. the dimension has only one way in or out, and that's the mouth of the portable hole.
2.) You can't pull it through. As soon as you pick up the hole from the surface, the opening closes. I would say this means that you can seal yourself in the hole, but then you're stuck there until someone from the outside lays it flat again. Of course, this is just my opinion, but it seems to make sense.
3.) While the hole is open, it looks in all ways like a regular 10' hole. If they could see you in a normal 10' hole, they could see you in the portable hole. Nothing says otherwise, and I think it would be terribly inconvenient not to be able to see into your own container.
-The Souljourner
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