All of your salsa questions answered.
Q. Should I use fresh or roasted veggies in my salsa?
Try this next time: divide all of your ingredients in half, and roast half of them and put the rest in without benefit of thermodynamic alteration. Then taste the two, side by side. You'll pick up on some obvious differences (one will be smokier, duh) but should notice other things as well. The grilled veggies might be a tad sweeter (peppers), a bit less bitter (tomatillos), or maybe nuttier (avocados).
Q. Should I coarsely chop, finely chop, or puree the veggies for my salsa?
A. Yes, of course.
I was about to say, depends on what you want to use it for ... but then realized, even that doesn't matter. If you need something for a chip, both extremes work. A topping for grilled fish? Again, both. Thick and chunky, thin and soupy, either way. Just depends.
Q. Chile peppers: seeds in or out?
Seeds in adds heat, while removing the seeds lets you maximize the flavor of that chile without scorching your taste buds. Me, I prefer focusing on flavor instead of just trying to out-heat the other guy, so it's usually seeds out for me.
Q. Cilantro: just the leaves or include the stems?
I used to always pull the leaves off the stems quite delicately and meticulously, until one time I was running out of time and I just threw the whole thing into the food processor. The stems add a bit of a sharper, more intense flavor.
Q. Only veggies or how about fruit?
Get a little too crazy and you're looking at a fruit salad instead of a salsa, but a bit of peach, pineapple, melon, papaya, and definitely mango will work. But you start getting into berries or grapes, and then I think you're just showing off.
Q. Beans? Add them or leave them out?
A. Yes. For all the reasons above.
Q. Spices? Should I let the produce stand on its own or do I need to doctor it up?
A. Yes. I'm a big fan of cumin, even though I don't know how to pronounce it. Just like with seeds, make a batch and divide it in half. Keep one batch plain, spice up the other, and check out the difference.