@Kaarme True wanting kids or not is something that needs to be discussed rather early in a relationship. Along with how and other such details. This falls more under thing unrelated to sexual orientation and all that really changes is what is important in such a conversation and what barriers would need to be overcome.
I wouldn't say this is anything worth noting however as proper communication is a vital part of any social construct. Friends, loves, family etc it does not matter. The location is obviously an extra variable but this still becomes a matter of compatibility without sexual orientation truly mattering. If you wish to be together despite laws then you must simply adjust to accommodate those laws. Moving or getting them changed work best but if not feasible it is just a matter of not being compatible.
Point is there really are to many details like this to discuss for it to make a dent in the overall picture of straight vs gay vs bi vs etc relationships. There will be a million different things that need to be dealt with or they sour the whole thing. Thats why being on the same page is so important and the differences between partners like this are more or less negligible. Not something you need to concern yourself with unless it is specifically important to you in which case it would always be a point of discussion.
EDIT :Also there is always an option. Hetero relationships are just an easier option logistically. Though it becomes a game of weighting love and the person against those difficulties. The value of a good match would generally be more than overcoming regular issues however. It just depends on the values being used which are highly subjective and open to lots of variables.