It is possible to upload multiple questions in Moodle question bank. The questions need to be uploaded in some proprietary quiz formats or pre-defined text formats. You can read more about them on https://docs.moodle.org/36/en/Import_questions. One of the popular plugins to import questions in Moodle using MS Word files is Moodle2Word plugin found on http://www.moodle2word.net/ and https://moodle.org/plugins/qformat_wordtable
At this point of time, importing via Google form integration is not available.
Yes you can import/upload question in various formats like GIFT, XML Kindly refer following link for more details.
At this time you can not integrate Google Form in Moodle, However You can embed Google Form in Moodle.