It's considered a best practice for authorizers to interview the steering committee or founding board members of a new charter school. The Charter School Institute does this and it's widely recommended by charter authorizers throughout the country.
Whether or not a charter school applicant has the capacity to carry off the formation of a new school is largely dependent upon the key people involved. Somewhere within the founding group should be the capacity to hire an effective administrator, identify and prepare a facility, ensure adequate cash flow and the numerous other things that need to be done before the first students arrive.
Founders should be asked about how the school's vision and mission were created, what their individual vision for the school is, what expertise they will bring, if they have any potential conflicts of interest, their understanding of the administrator's role versus the board's role, and other topics that will bring out the founder's knowledge about the school's governance and operations.
In my experience of working with founding charter school groups, it's possible to determine which schools will be successful right away and which ones will struggle, if approved. I have the advantage of getting to know most of the founders. I've seen several "overachiever" founding groups that have gone on to create some of the best charter schools in the state. Authorizers would be wise to also spend time getting to know the people who are applying for a charter school in their district.