Thoughts and answers in roughly the order you asked...
No matter which way you distribute your form, as a PDF or as an online form, you have limited control over limiting access. If it is a PDF, you can e-mail that to those four supervisors... but if they forward, copy, or otherwise distribute the form to others, then you may get more people with access to the form than you had intended. Likewise, with the web-based form: you can send the URL to the four supervisors, but if they share that URL with other people...
Your form will gather the data, and even provide simple analytics on the results, for you and/or upper management to view.
Without knowing more about the types of questions you want to ask, it's hard to say which way would be better - PDF or online. Unless you need a specific, exact layout, that also needs to be printed, then a web form is perhaps easier. The distribution and data are hosted by Adobe's servers and site... there is no local hosting option.
If using the web form, the supervisor would simply go to the URL of the form and fill in a new form. If it is a PDF form, the supervisor would open a new copy of the PDF, fill it out, and then click the Submit button on the PDF, thus sending the data to Adobe's servers.
The FormsCentral application is included in the Acrobat Pro XI box, but that doesn't include any of the actual service... just an application. Though if you have Flash installed on your computer, you can do all of the design work inside a web browser instead. Yes, I would spend the $0.99 to get acclimated to the product. If you're at all like me, you'll then see dozens of ways to use it beyond what you had originally anticipated.
I hope this helps,
Brian, thanks very much for your help on this. It was very useful and we began using the form today. Working great!
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