The list is a little confusing, especially the part about gear split two ways. It looks like you've mingled shared gear with "unshared" gear (for example, the 4 pounds of tent: is that the total weight of the tent you share, or are you each carrying 4 pounds of tent? You list only one pack, one cup and one spoon - but I asssume you each carry one?

Also, just because I'm too lazy to look up your previous posts, could you remind us where you mostly hike?

Having said that, some specific comments would be:

It appears that you've eliminated all the low-hanging fruit, like unnecessary spare clothing, extra pots, chair kits, climbingn ropes, and such. (Good job!) Now you're down to deciding how much money you want to spend.

You can save about a pound on sleeping bags, if money is no object (Think Western Mountaineering's Extremelite bag series, for one example, at about a pound and a half per bag.)

A 4-pound tent isn't too bad for a two-person tent, although there are lighter tents out there. (The Big Agnes Scout and Fly Creek Platinum are two that leap to mind, and weigh two pounds or less. Tarptents would be another option.)

Do you really need the groundcloth? This will depend greatly on where you camp. Around here (Ohio-Kentucky-Indiana-West Virginia-Virginia) a ground cloth isn't necessary most places; a tent floor is sturdy enough by itself. Of course, a ground cloth will keep the exterior floor a bit cleaner.

You mention a rain gear top - what about rain pants? I find them indispensable -but then, I hike in shorts, so they do double duty as long pants on a cold morning or in camp. Again, this will depend a lot on where you hike.

To get really picky, I don't carry a whistle - again, locale has a lot to do with it, and leaving it out certainly won't make your load noticeably lighter.

Your pack choice makes a lot of sense. That's not an unreasonable weight (at least not to me), and you're spending it on suspension, not gimmicks. Deuter packs are well-made, and the suspensions are incredibly comfortable and supportive. I've never been able to dial in as good a fit with the ACT Lite line as I can get with the Osprey Atmos 50, which weighs about the same as the Deuter ACT Lite packs - but that's just me, and doesn't reflect any objective criticism of the Deuter packs. I've used the ACT Lite 50+10 and the ACT Zero 50+15, and found them comfortable, just not as comfortable as the Atmos 50. There will be some who will, with justification, argue that they are overkill for the light loads you are carrying, and you should take what they say seriously. Try on some lighter framed packs that they recommend - some may provide equivalent comfort, but in the end don't be afraid to stick to your opinion that a bit more suspension is justified by your back injuries.