>>I would like to create a Membership form which includes a waiver
You could add a hyperlink to your form that points to the waiver page (FormsCentral/Design Tab/Insert Link). Or you can add a formatted-text field and include the paragraphs directly on the form.
>> I also want my customers to sign the memebership form accepting the terms and conditions of the waiver using an ipad. Can I have a signature area on the form and can I then print out the filled in form?
Sorry, signature field is not currently supported in FormsCentral. The workaround would be to add a required Check box field, that will require the user to check it as "agreed" to either continue or complete with the membership-sign-up process.
Hope this helps,