Please provide a link, so I could see this form http://prntscr.com/gtiw5e.
Free version of MailChimp allows to create only 1 form.
You can disable chat in Theme Options http://prntscr.com/gtx1wz.
Go to Appearance > Widgets > Shop sidebar > http://prntscr.com/gtx3ji, dont forget to create variable products with attributes.
