Winter 18 <lightning:datatable> problems

5) I noticed you are using initialWidth: "50px", the value of that prop should be an javascript number e.g. initialWidth: 50

Also there is not type id. Hence that column is gonna fallback to type text which is OK in your case I think.

1) lightning:datatable does not allow to react to a click or double click over a particular row. This version of the component is read-only.

Row level action I think is what you need. Its coming in next release. Basically you can have a column type="actions" and the cells of that column have a buttonMenu with the actions you want to apply to rows.

is there a work around for that today? Not ideal but you can use checkboxes and actions button(edit, remove, view) outside of the table, those button could be disabled if more than one row is selected or no row is selected.