Is there anyway to add the Mic icon to the Swype keyboard? I really like the 3rd party Swype keyboard, but it is missing the Mic button.  Is there a gesture or something to engage the Siri Microphone?
No, this is currently not possible due to restrictions with 3rd-party keyboards in iOS.

From Apple site:


  Custom keyboards, like all app extensions in iOS 8.0, have no access to the device microphone, so dictation input is not possible.