What can groups in the Definition Phase do to help them get through the challenging task of getting the needed 10 votes on 40 questions?
No. The Definition Phase is not a thing you just get past. It's not something you work around, dodge, or hack through. It is part of the process, and that part of the process should be respected.
The goal of the Area 51 process is to gather together a group of experts and enthusiasts in a field and get them to begin the process of building a site. These are the people the site will be constructed around.
The Definition Phase exists to create a series of questions that will show what kind of site we're getting. These questions will decide what is on-topic and what is not. You said:
At this point, it's not a matter of whether its a perfect question or not. Once the site is Beta, the upvotes and downvotes will determine that.
If you can't decide what is a good question or not now, you certainly won't during Beta.
People should not vote for a question that they wouldn't otherwise just to help the site get into Beta. They should vote for a question if they truly believe that it is a good question that helps define what the site should be about. That's the whole point of the definition phase: to get an idea of what the site will be about. If people are voting for any other reason, then they are corrupting the process.
The goal is not "to get to Beta"; it is to create good sites. And if you can't reach the 40 question threshold without shenanigans, then maybe your site won't be very good.
We should not encourage any corruption of the process. Even if you're at 39 questions, and one question has 9 votes, you still should not encourage someone to upvote it just to move on to the next step. If it's a good question, people will vote it up. And if only 9 people think it's good... tough!