1) Can one edit and or add or delete and save to an XML file locally from within Flex and after saving can the changed XML file be sent to the server?
2) What is the simplest way to save input into a form made with Flex (i.e. age, name etc.) at the server side?
HTTPService class might be what you're looking for.
You could edit the XML in memory, you could save to the server running your Flex app, then send it to some other server. To be clear check into how the project had been created. A Flex project is not a desktop project.
If you application is an Air application then you could save locally, then use an HTTPService to send the XML file to a server.