is it possible to search leads by forms and see if a form is used more domestically or internationally?
Well, you can run 2 Smart Lists constrained by the form name and country/region But you can't use the form as a "first-class" object in reports.
One other cool option (that would be a little more work but give you a side by side analysis) is you could leverage a People Performance report, a couple of smart lists and a segmentation.
Basically, I would first create a segmentation with segments for Domestic and International. Let that populate and segment your people into the domestic and international buckets. Then, create a smart list for each form that you want to evaluate (this is where the work comes in but once you have it in place you can reuse it over and over). For each smart list, the smart list criteria would be "Filled out form [insert form name]".
Finally, create a People Performance report with custom columns (these would be your smart lists - you can add up to 10 at a time) and group the report by your segmentation.
I hope this helps!