Regarding the health of kids, from what I read, while most of it was positive, there were a lot of experts who thought that there were too few studies done, some done or interpretted the wrong way, some with hidden agendas (whether pro or against), and most of them were focused on lesbian parents.
The coming decades will provide many more studies of a higher quality and that will provide much more information and insight into how children with lgbt parents develop.
I also think that as a society becomes more and more accepting of the lgbt community, that this will make it easier and easier for kids too, whether they are gay themselves or whether they have gay parents. Personally, I expect the situation will get better and better.
Some countries are definetly not ready for same-sex marriage, let alone same-sex adoption. And of the remainder, some are more ready than others.