I know of someone who had the TT, but without lipo. She was correctly advised by her surgeon that many women go into TT surgery thinking they will come out with a totally flat stomach, and that just isn't always the case. Some are lucky, and do, but many come out with not so much a pouch, but a bulge... meaning the tummy protrudes very slightly almost like many women do when they're bloated with PMS. If that's what you mean by a "pouch", that's normal for many patients. If you still have somewhat of a flap, your surgeon should be willing to address that.
The numbness usually goes away gradually, with some people taking a few years. Your surgeon is correct in that the nerves which were severed need to regenerate. I've heard that lipo done at the same time as a TT can make the recuperation time longer (as well as the surgical risks higher), so that may also account for the length of time it's taking your nerves to regenerate. Some people feel "pins and needles" while they're healing. I believe the typical healing period is about a year, before normal feeling becomes close to normal. However, every patient is different, and some never get complete feeling back. The hardness is also very normal, and may also last a few years. That's due to the tightening of the muscles, and is to be expected.
Regarding your question about the scar tissue...a TT is Major surgery, and does cause more internal scar tissue than people realize. The person I referred to above needed an abdominal sonogram for unrelated reasons a few years later. The sonographer tried her best, but after many tries said she just could not get a view of the area she needed to see, because there was massive internal scar tissue around her "C-section scar"...lol, my friend didn't dispute that part, but the scar tissue was obviously from her TT incision.