> > question:  how detrimental would daily or even occasional skim milk

If you are going to drink milk at all, go for the natural stuff, whole
milk. Yes it looks like LOTS more calories, but this is not a calorie
counting diet. You will be needing more fat anyway if you are reducing
carbos, and most paleo diets reduce carbohydrates. Fat is a lot more
satisfying and filling than carbohydrates, so do not carry over your
former diet prejudices into this new one. This holds true for
everything, avoid the fake stuff and go for the whole natural product.
No margarine ;--)

Milk does not seem to bother me but it does others. At first cut it
out for a few days then add a bit back in to see if there is any
reaction. Bread is likely to be a bigger negative than milk, when I
cut out only bread it makes a huge difference, the other things are
not as serious.

I suggest reading Ray Audette's book "Neanderthin" for another
perspective on this diet, his prescription is a bit different from
Cordains, hard to say which is better for who. I do well on Audette's
higher fat diet. In fact the more natural fat I eat the better I feel,
but weight loss is not my first priority. Though I have lost weight,
10 pounds or so this year.

The things that I see improved, are digestion, no constipation or gas,
reduction in headaches and body aches and pains ( I had a number of
sports injuries from college that have disappeared), fewer "down" or
"off" days. Some people claim to have a lot more energy but I have not
really seen that, though with many fewer bad days the result is the
same, I get a lot more done and enjoy life more. I started competetive
sports again after 20 years off, with my pains gone it was easy.

If your main need is to lose weight, you might want to go the low
carbohydrate route, it seems to work. Cut out bread and potatos and
rice etc, including sweet fruits, and eat non starchy veggies and meat
and other high fat/protein foods. The difficulty most people have with
this diet is that it gets boring pretty fast, you really have to think
of ways to get enough calories just from fat and protein. It took me
about 8 months to adapt to it to where I do not want carbohydrates in
excess. I still eat plenty of fruits and starchy veggies, but have no
trouble avoiding breads and junk foods, they taste so sweet. I use a
lot of spices now, and am learning to cook veggies in ways that help
avoid the boredom.

By the way, I started feeling better from the third day after starting
this last summer. It was so amazing.