No basically only KSA, Syria, the US and European states wanted him out. Jordan quietly backed Iraq and so did many Palestinians and others. Most of the world went along with the US and KSA because by then the USSR was washed up, leaving the US the only superpower with virtual carte blanche.
Er, no. Directly participating and supporting combat operations were the nations of Argentina, Australia, Bahrain, Bangladesh, Belgium, Canada, Denmark, Egypt, France, Greece, Italy, Kuwait, Morocco, Netherlands, New Zealand, Niger, Norway, Oman, Pakistan, Poland, Portugal, Qatar, South Korea, Saudi Arabia, Senegal, Sierra Leone, Singapore, Spain, Syria, the United Arab Emirates, the United Kingdom, a Mujaheddin contingent representing Afghanistan as well as the US itself. Indirect support came from Japan, Germany, China and the USSR. And note that the REASON Japan and Germany could not contribute forces was their post-WWII Constitutions not lack of commitment. Further China offered to deploy several divisions of air and ground forces IF the US would provide transportation while the USSR, (Russia specifically as you'll note several nominally WP forces are already involved) offered air and ground forces as well. Both were firmly but polity refused on political a political basis. (The Arab coalition partners did not want Chinese or Russian troops on the ground)
Palestinians that 'supported' Iraq were few and not very vocal and that's understandable given the Iraq had an active program to drive Palestinians out of Kuwait through intimidation and harassment.
And yes if you noted it is likely that one of the Mujaheddin fighters from Afghanistan was probably Osama Bin Laden as he specifically cites the Gulf War and the KSA governments allowance of 'foreign' troops into the country as the catalyst for the creation of Al Qaeda. He was promptly sent out of the country before the Saudi government had to officially "notice" him and he always resented that the government didn't "trust" that God would protect them. (Which is why it was always silly to try and hint at connections between Iraq and Al Qaeda since they hated each other more than the "infidels")
It is a known fact that Iraq had almost no support, (certainly no active support) and that the international community actually came together in a mass on a scale not seen since WWII. Iran was litterally the ONLY nation Iraq could attack without immediate and strong opposition from around the world. Having said that it is likely that Saddam got the idea that since he'd had huge support for attacking Iran that such support would continue if he invaded Kuwait but the actual "logic" of that process is and was highly lacking in any form of backing.
Randy