No. It adds inconsistency to the deck. Even though you think your mana base is perfect, you still have draws where you don't have the third color.
I think Tec Edge is really good, but if you do want to splash a color I think it should be black and not red.
Yes, because you have to adapt to the metagame.
Tec Edge is really good.
Yes, because the mana is free. There's no reason not to, and you get so much more power.