In Endless Space, I can choose reactions that are "Selfish", "Helpful" or "Hostile". The "Helpful" options often benefit other empires, while the "Hostile" options often hinder them.
Do my choices have any affect on my diplomatic relationships with other empires?
I don't think so. AFAIK the events don't have any effect apart from what you see on the choice screen (and the subsequent screens, if it's a multi-choice event, or one with consequences of some sort).
EDIT: if you don't mind spoilers, here are the exact consequences of each of the events: http://endlessspace.wikia.com/wiki/Random_Events#Interactive_Events. none of them seem to have any effect on diplomacy, except for one 'static' event (no choice to make here) which sets all faction relations to peace.
The answer is very likely no. In the diplomacy window there is a tool-tip how the your reputation is calculated when you mouse over a races avatar. It never changed due to my choices. Nor have I ever noticed the AI being influenced by the choice other than the stated effect. It's probably more a psychology experiment when playing against human player.
Whether AI is happy about your choice is probably more a philosophical question. Could a machine or an AI ever feel genuine human-like emotions?
