Yeah, basically, the flavors need to be heated in fat somehow, either oil, or butter, or fat from the meat. Sautee onions, garlic, whatever herbs, in oil for a bit and they will release their flavors. Then if you add other things to that and cook for a while on low heat, more flavors will be absorbed. In fact, if you have leftovers and leave them in the fridge overnight, the next day they will often taste better. Longer cooking = more flavor.
Arx's modified recipe looks pretty good to me. It is definitely possible to cook the veggies in the rice and add more flavors, but it's absolutely mandatory that you sautee the veggies in oil or butter first. (Actually, this is how fried ride is made. Sautee veggies, then add uncooked rice and let that get cooked in the oil a bit, then add the water and cook as you would normally cook the rice.)
Some things need to be added later. Mushrooms will burn if you add them too early. Tomatoes will burn too, are usually added after sauteeing is done. Peppers cook quickly and the flavor and texture changes a lot depending on how long they cook, so I usually add them late so they retain a bit of crunch. Onions, carrots, and fresh ginger are the things I cook first - they take the longest and can take the most cooking without burning.
I recommend trying your recipe again, Aqizzar, with Arx's or my modifications, then keep playing with it. I learned everything I know about cooking by trial and error, and some internet research, and I'm a pretty good cook now. I have a few secret recipes that never fail to impress.
As for salt, avoid it as much as possible. Adding salt will give you the illusion of flavor. Most people, especially Americans, are so used to such an enormous amount of salt in their food that they can't taste anything else. It's horribly unhealthy and it stops you from tasting the actual food. When I first stopped cooking with salt, everything tasted like paper for 2 weeks while my tastebuds adjusted, but now I hate the taste of salt and really enjoy my healthy food. If you do choose to use salt, use it sparingly. And never use pre-made spice packets, stock/bullion cubes, or "ready-made" food, because they are absolutely loaded with salt to hide the fact that they don't have any flavor of their own.
Cooking without loads of salt takes more time, but it is WORTH IT.