In regard to your first question: nope. I do not use motivators for behavior. A bribe of root beer for getting a shot? You betcha. But on a day to day basis, no 'carrots'.
Alfie Kohn has written a lot about the short-term/long term effects of incentives. In the short term, they do work fairly well. In the long term, not so much. The natural benefits are, in my opinion, the way to go.From my perspective, following directions, acting cooperatively and respecting others is somewhat the expectation, not the exception. When we see undesired behaviors, we correct them without punishment. Sometimes, this is "please go sit in the chair until you are ready to do X" (which gives them control of "when" or "how long") or "I need you to be in your room for a few minutes because I do not like how you are acting with me/talking to me" (making healthy boundaries) or "When you can talk to me in *this* (calm) voice, then you are welcome to come talk to me about this. Right now, I think we need to take a break." (teaching children self-regulation and self-assessment)
For me, the positives of not using motivators is that my son and I both have to find ways to deal with the underlying issues. If we have a hard time with something-- say, getting dressed-- and I tell him "If you get dressed quickly today, you can have X", I might get a few days of cooperation, but we really haven't addressed *why* he's having the 'getting dressed meltdown', which was the initial problem. So, I get a short-term fix but no real solution, and once he's bored with the prize, or finds that it isn't solving his problem, then the meltdowns would return. In this particular situation, once we figured out that he needed to deal with this challenge on his own (not sucking us in-- we were getting into a bad pattern of negative attention here) and earlier in the day, things became more pleasant.
If I instead just let the logical, natural consequences instruct, that helps so much more. There have been several times my son has said "I want to go to pizza" on a day when there was no way I was taking him out in public, and I told him so constructively. "You know, I have had a tough time because you have not wanted to follow directions or listen to me this afternoon. So I do not want to take you to a restaurant today. We'll try it another time." Once again, no bribe, just a statement of the obvious, and my open-minded suggestion that on another day, he'll be doing better.
I think, too, that when we get focused on sticks and carrots, we begin to get super-exacting and punitive about stuff that is relatively small potatoes. It also becomes a too-successful shortcut in disciplining, in my opinion. I know a few parents who do rely on this for 'everything', and what they end up rewarding children for is ridiculous. Not all 'rewarding' parents are this way, but I do see some parents who rely on punishments and rewards to change behaviors instead of, perhaps, embellishing their own 'parenting toolboxes' with new tools. Educating ourselves as parents and changing our parenting habits isn't always easy, but it's one of the most worthy challenges I have had the opportunity to take on. Sometimes, it's not just about changing our kids, it's about changing our selves.