Lard (or other fat) as a subsitute for butter in desserts for someone with a dairy allergy

You are asking not just to substitute for butter, but to reduce the total amount of fat in cookies.
All of the most common butter substitutes are going to be oils, margarine or other fats since they will perform similarly in the chemistry of the cookie. This makes it difficult to offer a simple substitution.

Instead, I recommend taking the approach of making cookies that are naturally lower in fat such as:

• Meringues - zero fat
• Macaroons - little fat, just in the coconut
• Macrons (french style) - little fat, without the filling -- just from the nut powder

or using recipes designed specifically to have lower fat content. If you google "reduced fat cookie recipe" you will find a wealth of results.

One site that looks promising, although I cannot vouch for it as I haven't tried the recipes is:

Good housekeeping's reduced fat cookie recipes

Another source for lower calorie recipes that are often pretty good, although not targeted specifically at reducing fat is:

Cooking light

Since fat contributes a lot of calories, you may have luck with their recipes.

The benefit of using recipes designed for less fat is that they are (from reputable sources) tested and likely to give you a better outcome than simply trying to substitute in a traditional recipe.

Also, you can try simply reducing the amount of fat in the cookie. This is going to be tricky as it will modify the chemistry, but you may be able to get away with a 1/4 to 1/3 reduction before you get completely unpalatable results, but this will require testing on a recipe by recipe basis. It also will not work well for cookies based on the creaming method, as the fat medium is part of the leavening (the purpose of the creaming method is to create a solid fat/air foam).

One final thought: some people say you can substitute apple sauce. You might try this on a recipe by recipe basis, but it will completely change the cookie. I think you will get better results with recipes created from the ground up to use less fat.

No, you can't substitute any of those for paneer. This should be pretty obvious given that you're trying to skewer and grill the paneer. It's a firm cheese that doesn't melt, while any combination of milk, yogurt, cream cheese, and butter will melt, if it's not liquid already. The best substitutes would be other cheeses like halloumi that don't melt, or else tofu. A firm cottage cheese would probably also do okay.

You also can't really use a cheese that melts in something like this. First of all, it just could never be the same texture, and the flavor would be a bit different too. But it could be worse than that. You didn't say exactly how much pumpkin, onion, and breadcrumbs you have in there, but generally, if you put a melting cheese in there, it's at best going to make the whole thing less solid and at worst it'll drip out as you grill it or conceivably even let it fall apart.

But you can indeed make paneer with the low fat milk, though. The texture just won't be quite as good - a little tougher, more dry and maybe even crumbly - since there's less fat and relatively more protein. With whole milk, 2L of milk makes ~350 grams of paneer, though that can of course vary depending on how well you drain/press it. Low fat milk won't have quite as high a yield, but you can probably still just start with 2L. The texture is probably the bigger problem. (And it'll of course be worse if your milk is 1% than if it's 2%.)