Few Queries Regarding Saas Project

Hello All,

I am working on a side project (A saas application) and have few queries .

1.What would you suggest how should i go about choosing right developers for SAAS applications. Specially when you are on budget and with little knowledge of programming / coding.

2. If i go for single DB for all tantent or db per client?

3.If i choose single db How would you make sure that each tantent only have access to his own data ( apart from logical isolation what can be done on db level) should i choose UUID for each tenant and thier departments and staff member for maximum isolation with in a same database ?

4.I am very pro privacy. As a admin of saas app do we need access to clients personal / business data ?

Say client may have many store and and staff working under him do we need to have access to that level ? i.e personal profiles , appointments, off days, sales or impersonate feature to access all the detail .

It would be great help, if anyone could answer these queries.

Thanks