Please let me know if we misunderstood the issues, the answers seem to be correct:
If these are custom attributes, you can re-order them by changing the Order number while editing these attributes. If the Price attribute is built-in (e.g. added via Marketplace) then it has a static order but other attribute you added can be re-ordered and appear before or after the Price.
You can add fields to this form only by adding booking attributes. If you mean adding listing attributes there (e.g. to indicate some listing-specific details) this would require code customizations.