how can we implement role based access? lets say if i have following requirements

1. If certain property fields are visible or editable only for a accessrole with skill State=CA or skill = English

2. only certain values in drop down will be visible in for a certain users

3. how can we leverage privilege, role based access, access of role to object, property security, access when??

Please let me know if there is any article related to these or it would be great if you can explain how we can implement the above reqs