Hey Erin,
Yes, all of what you suggest is possible to do with a bit of customization:
1. You can use the Create Task flowstep in a Smart Campaign for assigning a follow up task, but you'd first need a way of assigning the leads to the appropriate rep. My sales team is organized by geographic region, so on my forms, I had to make sure I was asking the lead's state as a required field. Without it, the lead would go unassigned. Then, as long as you also have assignment rules either in Marketo or Salesforce picking up on that state field change and assigning the lead accordingly, you can assign a task to the owner for follow up. Alternatively, if all the leads at a given show should go to one particular rep, you could just build some overrides that force assignment when the form is filled out to that particular rep. Again, all depends on your setup.
2. I accomplished the need for notes by creating a custom text entry field called "tradeshow notes". To make that info more front and center, it might be possible to pull in that information as a token into the task you assign to the rep too. I have never tried it, but I imagine it's possible.
Let me know how it goes, and happy to help!
-Jeff