Blueshirt, your questions suggest that people can know for certain why they got RQ or why their application is delayed. In fact it's really hard to know even the most general reason unless there is specific notation in an ATIP file, so people's guesses are only guesses.
Also, just because someone experiences slow processing doesn't mean that they did something wrong or made a mistake. Sometimes it means that the CIC is understaffed. Let's not read significance into every detail or delay unless we have some evidence to support it.
Finally, there's nothing wrong with entering Canada multiple times. Would this slow things down? Maybe, maybe not. No one here knows. We could guess. And freak ourselves unnecessarily and make ourselves feel like PRs aren't allowed to travel. But PRs are allowed to travel and there's nothing wrong with traveling as long as one meets the residency requirement. We shouldn't suggest that it causes delays or problems when we have no evidence of such.
It's the CIC's responsibility to process our applications in a reasonable, timely and fair manner. It is not our responsibility to contort our lives into a fantasy of the "perfect immigrant" who will be rewarded with speedy citizenship. There is no such thing as a perfect person, immigrant or not. We need to be honest and do our best. Let's not convince ourselves that we did something wrong because we went outlet shopping in Buffalo a couple times.