Hi, Justin. Here's my input on your questions:
1. If things sound great to you, then you have a proper set-up...that's really the bottom line. That said, I tend to follow the thinking that it's best to match the sonic qualities of the center channel and front speakers (generally called timbre matching), and that's much easier if you get the same brand name and get speakers that our designed to be matched. However, you can overcome some differences by using equalization on the speakers. If your receiver has an auto setup feature (and I'll download the manual and check) that does equalization, you are probably set. If things sound the same to you as they travel from one side of the screen to the next (so, the sound passes from one side speaker to the center channel, then from the center channel to the other side speaker), you're gold.
2. Bundling the audio and video cables shouldn't give you any problems. You do want to avoid bundling power cables with your A/V cables, though.
3a. Quality of cable does matter up to a certain point, but no further. Personally, I'd ignore the claims about the speaker wires carrying the different frequencies at the same speed. Monster makes good cable, but you'll be perfectly fine with other, much cheaper brands.
3b. I tend to think that the direction doesn't matter, but I do recall someone posting on here about it possibly mattering depending on a design parameter that I can't remember (I think that it involved the shielding or grounding scheme). Either way, if the cable has a direction arrow, it never hurts to follow that guideline. For other cables that don't have arrows - don't worry about it, just plug them in however you want.
EDIT: Okay, I see now that your receiver doesn't have an auto set-up feature that will try to apply equalizer settings to your speakers. No biggie - that would just help compensate for sonic differences between the speakers.
