Wheat Flours at Cook's Thesaurus discusses varieties of wheat flours and their substitutions in general baking, yeast breads, and as breading agents.
And here's a reference discussing "the carbohydrate-content, dietary fiber content and 'net carbs' in all types of flour": Carbohydrates in Flour and Baking Foods.
I consult these pages as jumping off points when I'm altering my baking recipes. I'm a big fan of mixing flours to come up with lower-carbohydrate and more nutritionally sound baked goods (white flour isn't the most nutritional option out there, no matter that it's one of the most common options in baking). Oat, spelt, and soy flours figure in a lot of my recipes (note that using soy flour calls reducing the baking temperature called for in a recipe by 25°F, and that soy has a very pronounced flavor that not everyone likes).
The more you learn about the various flour options, the easier it is to make substitutions with confidence, so I encourage you to do a bit of reading. Of course, if you're rushed, baking sites (ones that sell high-quality flour, such as Bob's Red Mill) tend to tell you right on the page how much of their flour to substitute for wheat flour.
As a general rule, the more whole grain flours you use the better because of their higher fiber contents. If you subtract the fiber from the carbohydrate count, you find the net carbohydrate of the flour in question, and it's the net carbohydrate that tells you how your sugar levels will be affected. One carbohydrate serving is 15 grams of carbohydrate total.
One cup of all-purpose flour has 95 grams of carbohydrate and 3 grams of dietary fiber, which gives each cup a net carbohydrate amount of 92 grams (which is 6.13 carb. servings). One cup of whole wheat flour, on the other hand, has 87 grams of carbohydrate and 15 grams of dietary fiber, which gives each cup a net carbohydrate amount of 72 grams (which is 4.8 carb. servings). Even if you're baking a bread that isn't particularly low in carbohydrate, getting the benefit of the increased nutrition and fiber from a whole grain flour will benefit you.
The meringue should be glossy and form soft peaks. When you take your whisk out of the meringue it should look like this:
The French say that when you take the whisk out of the meringue, it has to look a bit like a bird's beak, hence the way the meringue forms a soft peak slightly pointing downwards.
But to be honest, I don't believe that is you problem. I guess you just undermix your batter. People often say it has to fall like a ribbon or like magma, but I always thought that is hard to imagine. You can take a knife and cut through the batter. If it flows back immediately, it's ready. But let me tell you: One or two strokes too much with the spatula and the batter becomes unusable.
And one tip I can give you: The process of transferring the batter into the piping bag also 'mixes' the batter, so maybe don't go too far if you are unsure.
And as already said, it is important to tap the the tray from the bottom after piping as it helps to remove any air bubbles in there. Also, always pipe straight from the top (90° angle). This also helps the batter to smooth out.
I wouldn't recommend you to chance the amount of powdered sugar, as the French use Tant pour Tant (TPT) for their macarons, which means fine almond meal and powdered sugar are mixed proportional to each other.
When mixed perfect, it looks like this:
http://1.bp.blogspot.com/_WhPHUKwckUw/S4WP1eBE7pI/AAAAAAAAB00/gYqFjGOvEiU/s1600-h/5.jpg
When gone too far, it looks like this:
http://3.bp.blogspot.com/_WhPHUKwckUw/S4WP-q8RrdI/AAAAAAAAB08/7R6uO1uGfBQ/s1600-h/6.jpg
Maybe try counting your strokes while mixing, some people say that it helped them.
Best Answer
Here I'm assuming that you mean macaroons as in the French patisserie macarons rather than the simpler coconut or almond based macaroons.
In any case almond meal and almond flour are essentially the same thing, both are almonds ground into a fine (or not so much in your case) 'flour' or 'powder'. Apparently, almond flour is made from 'blanched' (almonds which have had their skin removed) almonds whereas almond meal can be made from either almonds with their skins on (whole) or 'blanched'. I have, however, always found them to be used interchangeably.
If your problem is graininess, then you could either sieve the ground almonds before using or blitz/grind them finer in a food processor until the desired consistency is reached, however if you're grinding them in a food processor make sure you do it in small batches or if you're making macarons blitz them with the icing sugar (for the tant pour tant) to avoid making almond butter. Personally, I would do both to achieve a fine powder.