How to import (stream) data in Drupal and save the visualization as nodes - similar to datamasher.org)?
Nodes arent the best for storing data as such. I would suggest the data module for storing the datasets. (support for import via feeds is underway)
To display some results and charts there is several ways - have a look at forena for example. You could then create a node type that would save the parameter values for forena reports and upon node node display show the report. Similar functionality can be achevied vith views (not so much fomratting though).