The thing that really gets me is ENBoost. Most of the effects are actually fine just turn off detailed shadows. Also double check that the Steam Overlay in-game is not enabled as that will also cause transparency problems. ini files and is not forced through your control panel. As for the transparency issues you are having. However, ambient occlusion is fine about 90% of the time as long as the setting itself isn't turned up too much. Personally I find that detailed shadows is broken and causes massive artifacting in the corners of the screen. Boris has commented that nothing can really be done about this and that he has done everything he could. There are also some smaller issues that are also engine related such as water displacement acting weird. Most noticeably with ambient occlusion and detailed shadows. There are a lot of limitations that the engine has that make ENB have issues with certain effects.
