Basic questions about creating a vertical crm

Basic questions about creating a vertical crm

I'm brand new to this and have a few questions:
  1. I want to use the vertical i am building for myself to test it and use it in my day to day, so i can refine it.  If the app is not published is this possible outside of a sandbox which would no be ideal for live data?  
  2. After I publish a vertical, can i use my own app with my zoho one account for free?
  3. What if i want my vertical to have tie-ins to other apps from the app store?  For example for sms triggers, zoho doesn't seem to natively support sms/mms.  So i have to use a third party connector from marketplace.
  4. What about tie-ins to other zoho apps like campaigns?
  5. Can i set a different pricing structure for different user levels?  IE a user in a company/group with global access to all records would have different price than a user with limited access to only their own records?