We'll respond shortly.
"Is there way to test if the Active Record associations you're trying to eager load with :includes are actually loaded?"
One solution would be to call .loaded on the proxy object which control the access to associations. Another would be to count the sql queries that the block of code makes.
When you query a table with a column containing string values, if you do Model.where(:string => 0) without using quotes for the 0, Rails will not to_s the 0 for you and the query will return the entire table.
"What's the best way to deal with cross-window communication?"
"If you want to read remote files, the best way to do it is using GET requests."
One alternative would be to use run 'cat filename' which gives you a text output that you can store. But the issue with this option is that it will add control characters in your text which cannot be parsed and can consequently make everything blow up.