1: The 1st thing that came to my mind when I read this was my smart phone and how it's linked up with all these different App';s like my email, my Google drive, inst gram and Google + and how it syncs with these programs. I love/hate the sync feature for 2 reasons' 1 it's awesome that you can get all of your contacts and your pictures but i noticed it poet's all of your pictures in there and I decided i didn't like that too much especially when I took pictures of my grandson being born and some of those pictures were for parents eyes only and well let's just say I had one very upset daughter in law. I however did find that it's very useful to put your account on private and your pictures viewable by only you so that the internet does see inappropriate pictures like that.
2: Great example Victoria,
I have multiple entries for people due to merging several different phones over the years along with corporate contacts and various Internet accounts. I've actually linked the incorrect contacts together and had to go back and fix them due to the error. Luckily I didn't mix a lot of content but it I have accidentally merged the wrong calendar items in the past in a similar fashion. How could your design in concept mitigate the risk?
3: Do you think that a database would make a design more complex to implement or make your circumstances easier to design and implement? Databases by nature reduce data redundancy which improves data integrity enabling you to reduce coding since you don't have to write data locking code, etc. Security features of database add an extra layer of security if used correctly where sequential data structures may have limitations. Any thoughts?