I'm happy to report that the 3M strips are awesome at holding this up!
I live in a house, so the only one I would have to worry about stealing it is my niece, but she's 2 and can't reach that far yet!
As for the corners, they are cut sort-of diagonally, and then overcasting makes them look all fancy!
I'm lucky to have a craft room! My roommate (aka my mom

) had her office in the room to begin with, and I had a craft corner in the living room. My mom decided she wanted her desk in the living room and we were going to have the spare room be a toy room/bedroom for when my niece and nephew would come stay for the weekend, but by that time, my yarn had started multiplying and taking over the whole living room (not to mention my cat stealing full skiens and carrying them around the house!) So, I got the room for my crafts!

Its great because I can shut the door and not have to worry about my cat or my niece stealing things! My nephew just comes in a sits in my recliner and looks at my patterns and tells me who is who of my cartoon character ones. (He's 4 and in the autism spectrum, but he's doing awesome and finally talking in complete sentences!)