Have the LibreOffice developers considered a Kickstarter project for the GUI?
I do not believe that funding opportunities such as Kickstarter have been considered to fun GUI development. Feel free to hop on the dev channel on IRC (#libreoffice-dev on freenode.net) and ask the developers questions.
Were you interested in funding a particular piece of UI development?
Update: See the Crowdfunding page on the TDF Wiki for more details.