On the terms and conditions the only thing I found about cheating is this:
Tickets or Rewards or in any Program-related materials. Microsoft reserves the right to disqualify Participants and void their Tickets if found to be tampering with or abusing any aspect of this Program or are otherwise not in compliance with the Terms as solely determined by Microsoft. All questions or disputes regarding the Program, including without limitation, those involving eligibility, participation, fraud and abuse will be resolved by Microsoft, whose decisions shall be binding on Participants.
This basically gives them the right to do whatever the hell they feel like, and it's not like they're doing it now anyways. If you complete a puzzle fast enough, they WILL delete your points whether it was from a bot, aide, or just pure speed.
It's very clear that they have no intention of actually tracking down cheaters. They know perfectly well that pure speed doesn't mean that you're cheating, but they could care less. They're just looking for excuses to delete your points. I'd also like to point out that they said Microsoft holds the right to disqualify points/prizes due to abuse or fraud or anything not in compliace with Microsoft's terms, but aside from that, they have no visible "terms" on what they consider fraud or abuse. They could delete legit points and say that they consider those to be fraud/abuse even if they're not, and they're already doing this.
In short, just forget about this goddamn promotion. Microsoft wants you to spend hours upon hours of doing the puzzles and if you manage to do it quicker (bots are an acceptable form of abuse, but not aides or pure speed. That's unacceptable), they'll just delete your points. Funny thing is, bots also give them search hits which they're getting money for, but when they invalidate your points, they don't invalidate the hits you gave them. They still keep those.
They just want to look for ways to keep your prizes and still get their money. Yet another way that Microsoft is ripping you off. Just don't bother and forget about this promotion.