More evidence of voter Fraud. Biden Fraud, page-781

The legality of privately raised money being used to pay for the audit has yet to clarified.

Also, if allowed, it has yet to be determined if will it be paid out via the Senate or directly to the auditors.

Yes, the Senate has decided that it's worth the spend but they have capped their contribution.

The scope you outlined is likely to exceed that amount.

Based on social media posts (including the ones deleted by Doug) the actual independence of the out-of-state companies has yet to be determined.