Thats exactly what I do.
Plus you want to brown the meat itself (not the flour) to create flavor.
That depends. As the roux browns (when you brown it separate from the meat), it takes on a nut-like flavor that can compliment the beef flavor. At times, I simply make the roux, and stir in enough broth to make a thick gravy, then add that to the stew. Other times, I want the flavor of the browned roux.
Cajuns cook their roux to almost black before putting into etoufe' (sp). Also, you can use other liquids to flavor your roux as you make it into sauce, such as Worcestershire, or A1, or add garlic, onion, ground pepper, etc.
As with all great dishes, there is no one right way to make it. There are several techniques that will all produce a wonderful stew. I like to use beef heart in my stew, as it has such a rich, beefy flavor. Some people like to brown a good chuck that's been cut into bite-sized cubes, with the fat on it, until the fat is crispy good. Some like to cook the stew in a covered pot, in the oven, all day. Others use a slow cooker and let it simmer all night and day. I've used both. I've also cooked it in a covered pot on the stove top, and I've made it in 40 minutes in a pressure cooker (It tasted like it had been cooked for 10 hours when made in the p.c.).
The only wrong way to make a stew is to overcook the meat, so as to dry it out, or to burn the stew, or to make it too watery. I'm thinking that adding pumpkin pie spice would mess it up as well. But that's just me.
The point is, there are so many great ways to cook and make a stew. You can add tomato if you want. You can add so many different herbs and spices. You can tailor your stew to really make it unique, and delicious.
My DW really doesn't like flour-based gravies and sauces (I prefer them). So, usually I thicken my stews with a cornstarch slurry. Or, I'll divide the stew in half, and make my half with a roux, and her half with the cornstarch slurry.
As everyone around DC knows by now, I'm into experimenting, and trying to create new and interesting meals, sometimes altering tried and true techniques and flavors. At times, it make the meal wonderful. At times, I have to force myself to eat it, as whatever I did, wasn't as good. But that's how I learn. And I've been doing it for 35 years. You learn a lot in that amount of time. But I still consider myself a well-versed armature. Cooking is such a brad field that if you desire, you can keep learning new things for a lifetime.
Seeeeeeya; Chief Longwind of the North