There are a lot of programs that interfere with Steam for some reason. I don't know if this could be the cause of all your problems, but I used to try to run steam and it would just idle in my processes tray and never start once I installed nvidia network manager or something like that. There are a lot of programs though that steam has listed on their support site that do cause issues with steam running. I don't know if this would help you or not like I said but it would be worth a shot to look at the list maybe.