Change your list a little. Who cares if he eats his fruits and veggies ? Give him some autonomy somewhere . . The fact that he is very good elsewhere and when Mom is not there should tell you that he understands the rules -- he is just pulling your buttons and it sounds to me as if he is winning.
Look at the behaviors that drive you insane, and decide which ones are critical and which ones don't matter. I don't like jumping on the furniture, because it costs $$ and should be treated with respect to last, I don't like hitting the younger bro, cuz people also should be treated with respect. What stuff on the counter does he move ? And why ? Where is the anger coming from ?
Meanwhile, after your list is made, be calm and determined. Forget the slaps and the stolen toys, and the time-outs. Remember that he is still small enough to be "controlled", and simply require that he correct what he has done. Help him to put everything back in its place when he empties your counters. But make sure he assists -- even at first if you hold his hand so he has to stay with you while you do most of the work. He has to pick up and replace at least one thing.
When he jumps on the couch, remove him from the scene of the crime. Make him pick up the pillows and put them back on the couch. Is there some other activity he can do to release his energy ?
In the mix of trying to do housework, grab some me-time, care for a 16 mo old, and find energy for your oldest, what is getting lost ? Is he getting the shaft on some Mommy-time ? Or on more age appropriate activities? Are there things you can do with him, while little bro is in a stroller or something ? Find things that ignite his sense of curiosity and help him explore the world some ? It's still summer, so getting out and about is an option, and it sounds like both you and he will have more peace doing things in public where he behaves better, and you can relax and enjoy him more.
Good luck. Parenting isn't easy, and child #1 is what I call, "the experimental child" -- by the time #2, 3 and 4 come along, we have already jettisoned our straightjackets and we go with the flow a little more. :-) The first one we somehow assume must be perfect or we are bad parents. See if you can listen to him and enjoy him, and when the good times increase, the acting out moments will magically begin to decrease. ;-)