All the points that you stated is right. I want to ad more poin, I hope it can help. Other important things are about the project it self and whether there is legendary member that join the signature campaign of the bounty or not. If the project will make an important contribution to the cryptocurrency world then the project will most likely be a success. Legendary members are people who have experience so follow their decision is a good thing. The deeper analysis are about market condition, statistical data about the websites and technical data about cryptocurrency they use, websites and products. Usually famous bounty manager has done the analysis so that he can guarantee the bounty participants to get their reward.