simple web app using google sites and app scripts

I would like to create a simple web app using google sites. Two things are embedded: 1. Google Maps 2. A google sheet There should be 6 column headlines: What (text) | Where (location on google maps) | When (date & time)| Who (text) +...) | Join (button)| Comments(text + text +...) Functionality: 1. Row creation 1.1 Everyone with access to the website should be able to add new rows. 1.2 A creator of a row has to be logged in with his google account. 1.3 This google account is associated with being the creator of this row. 1.4 The admin of the site and the creator of a row are the only one who are allowed to delete the row 1.5 The admin of the site and the creator of a row are the only one who are allowed to edit the columns: What | Where | When 2. Join Button 2.1 Everyone with access to the website can click on the button in the "join" column. 2.2 Clicking on the button opens a dialog with a textfield "insert name" and a button "confirm". 2.3 If the user clicks on "confirm", the name is added to the "Who" column of the corresponding row. 2.4 Each google account can join "Who" only once per row. 3. Comments 3.1 If a user clicks on a cell in "comments" then a dialog should open with a textfield "comment" and a button "confirm". 3.2 If the user clicks on confirm the text is added with a "|" seperating this comment from the previous comments. 3.3 The cell is stretched horizontally to the right. [login to view URL] 4.1 When a new location in a row is added, a marker should appear on the map corresponding to this location. 4.2 When a new location in a row is added, the map should zoom out so it incorporates all current locations in the view.