I have not seen it mentioned, but two items I have included in my first aid kits are a finger nail clipper and an eyeglass repair kit.
The finger nail clipper is a God send when needed, a knife just doesn't work on a hangnail and can make matters worse.
A $2 eyeglass repair kit from the drug store, self contained in a plastic tube, has helped others in my party more than once.
They are both small items, inexpensive and perhaps extravagant, but they do come in handy.

I always found carrying a nail clipper a luxery outside a Urban enviroment. When I do notice I should have clipped my nails and haven't got a clipper handy than I use the scissors on my Champ. Works just as well.
Talking about FAK's. In addition to carry a FAK in my rucksack (on hike's) I carry a pocket FAK:
1x triangular bandadge
1x surgical gloves
1x large field dressing (also does the job of a small one)
1x safety pin
1x paper bag

I roll the contents around the field dressing with the tri. bandadge around the outside, close it with a safety pin. Eh presto! I got a very compact Pocket FAK.
I stumbled upon this idea as I went clubbing and felt stupid not carrying any FA gear in a place where so much can and does go wrong.

Anyone can think of any lackings or un - useful items?

Yep, I agree that they are both good additions. I placed an eyeglass repair kit with my sewing kit. I also carry both finger and toe nail clippers in a pouch with a couple of hemostats (sp) that is in our med. kit.

I have a nail clipper in my fishing kit. It found a lot of use in the field altough it was never used for clipping nails. On rare occassions it was even used as power grip tweezers (you have to be careful there) when the regular tweezer couldn´t get enough grip. So if there is enough space for the clipper it´s a good idea to add it to the kit.
With a pocket FAK there are many things lacking for an obvious reason. I´d add a couple of gauze pads if the still is room for it.

You bring up another topic of to consider, tweezers. I opted for high quality tweezers for each of my kits. I purchased from Mehaz, a Swiss company, about $18 each, but well worth the money; stainless steel, sharp, pointed. I also added 6 blood lancets, the kind used to test your own blood. They are small, disposable and sterile, ideal for digging out splinters, etc.