Hi M.,
I can sure empathize with yours and your wife's situation, as my oldest two kids sure put me through the paces during their toddler years--they're 17 mos. apart.
Once, I *lost* my son in a Kmart. I looked away for 30 seconds, and he just vanished. I was terrified! He came strolling in the front door of the store what seemed like forever later, when in fact it was probably only a couple minutes(I have no clue, really. It really seemed like forever but I was scared to death that he'd been taken), but let me tell you, that was one of the most frightening things I've ever experienced as a mother. The others were when he fell out of a cart and onto a concrete floor, and the time he swallowed a nickel. Taught myself the Heimlich for that one lol.
They were both constantly getting into things(condiment war, perfume and make-up testing), taking off out the front door(caught them all the way down by mailboxes one time), eating cat food, whole rolls of paper and sometimes toys in the toilet, dresser diving onto the bed(they made stairs out of drawers to get to the top), oh the list is endless.
My point is that yes, this is more than likely a phase, and you will wonder how any of you survived it.
I suggest child proofing as best you can, and then doing it again when you think you're done. And someone else mentioned leashes--get TWO of them, especially for malls/shopping and times when you will be dealing with traffic. I got wrist tethers for my kids, but now they have these cute little backpack ones. Let your kids pick out the ones they like.
For naps, put up a baby gate to block the hall so that the one not sleeping can't go down there and wake the other. If you only block the door, they can go to the door and bang on it, but at the end of the hall, they're further away.
The couch cushions, try taking them off the couch first, and see what they do. Sometimes, stumping them really helps. Sometimes you have to get really creative at beating them at their own game, so if *you* take them off first, and hide them, they'll move on to something else.
When they're doing something you don't want them to do, give them something to do that you *do* want them to do. Some of the colors that won't mark on anything but the special paper, a book, a new toy, something to divert them.
It was mentioned several times that consistency and follow-through is the key, and it is, and I liked one mom's approach of hands on both sides of the face and forcing them to look at you when you use a calm, but firm voice when you need to get their attention. Also, fewer words. That way when you *have* to yell in emergencies, it gets their attention.
It will take some trial and error to find what works with your kids, but realize this is a phase, and they'll grow out of it.
Good luck to you both, and hang in there!
K. W