Most hatred and prejudice toward the LGBT community is religion-based. Others are just afraid of the unknown.
No. There are no stories of gay couples in the Bible, though there are people who have interpreted some Biblical relationships as gay, such as the relationship between David and Jonathan.
Why does it matter that the couple is gay? Couples argue in general. Why do people disagree? Why do people like different things? To argue is natural and couples need to work things out and discuss things, regardless of gay or not.
In the U.S. and Canada, most single gay people can adopt. Many areas allow for joint adoption by gay couples as well. Gay people are only banned from adopting in some countries, and this is due to ignorance and prejudice.
As of 2014, about 20% of American gay couples have children.
There is no such thing as illegally married gay couples. There are only legally married gay couples (with or without state recognition), and unmarried gay couples.
As of 2017, gay people can technically adopt in all 50 U.S. states, but they are still routinely denied in some states. Single people (gay or straight) are allowed to adopt in all states except Utah.
Research shows that the children grow up happy and well-adjusted. Some studies have even shown that lesbian couples produce the most well-adjusted children when compared to straight couples and gay male couples.
Single people adopt more than gay couples, but only because there are many more single people in the world than there are gay couples.
Gay people are equal, but in some countries, the law doesn't reflect that. The problem stems mainly from old misguided beliefs.
married gay couples are prone to the exact same illnesses that married straight couples get.
Some wish to. Others do not. It's probably about fifty-fifty for existing cohabiting same-sex couples.
There is no law against it, and there have been gay people in cartoons, many of whom have had partners or who dated. See related links for a list of gay cartoon characters.