At a Loss

I am at a total loss as to what to do with this little cutie. She has turned into a holy terror lately. I can not believe how much destruction can come from something so cute and little. Kate is so different than Eliza it is interesting to watch as they grow. Eliza will ask for something and if I tell her no she will get mad and throw a tantrum or yell and have attitude with me. Kate on the other hand will not ask for something because she knows I will probably tell her no. She will just sneak it and go off and hide with it. She snuck the frosting out of the fridge the other day and a cupcake off of the counter, went into the laundry room and hid in the corner as she ate the cupcake and handfuls of frosting. Funny to anyone that isn't cleaning it up.
She also has a paper fetish. Anytime she gets any kind of paper near her she rips it into thousands of little pieces. It is so annoying to find tissues torn to shreds in her room so when you open the door it looks like it has snowed in there. I can't leave toilet paper out where she can get to it otherwise it is unraveled all over the bathroom (no, she isn't potty trained yet-VERY frustrating). She doesn't color pictures, she rips them up and leaves them all over the floor. I don't understand it, but I try to let her rip as much as she wants at the table as long as she cleans it up. Strangely enough, she doesn't find it appealing in that setting and so therefore I continue to find various types of paper ripped apart all over my house.Kate is so unmotivated to be potty trained I could pull my hair out about it. She is 3 years and 7 months old and STILL is in diapers. She can go potty on the toilet, she just doesn't want to. She tells me she just doesn't want to. Rewards don't work, bribes don't work, and punishments don't work. I have tried everything I can think of to get her to have a desire to be potty trained. I have even made her stay on the tile with nothing but a shirt on so that she couldn't pee in her panties or diaper. It only works sometimes. She isn't even motivated by the "Big Girl Party" I promised her where she could choose the treat, movie, and stay up late. Eliza is not happy that Kate is not potty trained because Eliza is dying to have the party.
I have told Kate that until she is potty trained she still has to have nap time. Eliza gets to have quiet time in my room with activities or books that allow me to still have a little time to relax. Kate has to be in her room with the lights off and no toys or books. I have told her that as soon as she chooses to be a big girl she can have quiet time instead of nap time. She is still not motivated. Instead she chooses to punish and torture me with the naughty things she gets into when she is in her room for nap time. She has unloaded everything she can from her closet probably 5 times in the last few days (wouldn't you say so Laurel? It seems like I always discover this when I am on the phone with you). She has snuck into the bathroom and put a rag in the toilet and flung dirty water (yes, Eliza didn't flush after herself) around the bathroom. She has pulled so hard on the curtains that the rod bent and they came off the wall. She refuses to wear regular clothes and only wants to wear pajamas. If I make her wear something else, she changes back into pajamas at nap time. She also takes her pigtails out no more than 5 minutes after I put them in. There's more, but I think you get the picture.
I sure do love my Katerloo, but I am exhausted trying to find a way to discipline her in a way that is effective. I figure she is needing more attention since baby Tanner has come so I have tried to give it to her in positive ways, and still no progress. I hope I find something that works soon or I will have a breakdown. (There's authentic for you, Brynn!)