Chris, I’m sorry to hear this. From what I can tell, Braintree will only reject clients that they deem have a high risk business model. Please see this link https://articles.braintreepayments.com/risk-and-security/underwriting/overview. If this is a business model you want to pursue you might to provide a guarantor. We will need more information on the rejection in order to help further.
From the Dropspource perspective, we have implemented Braintree’s standard Drop in UI (https://developers.braintreepayments.com/guides/drop-in/overview/ios/v4) so there should be no technical issues as this is the most basic and standard way of accepting payments.
Regarding the save errors can you please hard reload your project and try and save again?