Residence Permit Questions

Does anyone have first-hand experience in applying for a residence permit in the Business category? I am single, so I am wondering if I can use an employee who has known me for 8 years as the required "witness" and what kind of questions will be asked of myself and the witness. And how far back do they go with the Personal History - your whole life, your residence in Thailand or your time in Thailand on 1-year visas? Do they expect any supporting documentation for this past history?

Am I right in thinking the mandatory three unbroken years in Thailand on 1-year extensions excludes any short trips out of the country on a re-entry visa?

I have dual citizenship, so will they expect a letter concerning the criminal record check for each country?

What would be any specific counts against me other than a criminal record? My record has been pretty smooth for the past 15 years or so, but I once took an employer to court, I once had a work permit application rejected, I once was fined for not notifying the Labor Dept of a change of employment (my employer's fault), and there were a couple of years when I didn't have a work permit. But all this is so long ago, I can't imagine anyone will care much.

Thanks in advance.