SX100IS - on tripod shot

What's your tripod? Some just aren't up to holding a camera steady, even when allowing the 10 sec. of a self-timer for things to settle down. Springy floors can also cause vibrations in tripod shots. Also, the camera focused on what it could see - the fluorescent lights. Thus it wasn't focusing on the people and they're blurred.

most compacts are programmed to focus at the nearest object. I'd say, if it is a planned shot, do not rely on the camera to plan for you. Set the aperture yourself, F8 or F11. Turn the focus ring yourself too. Take a few more shots just in case things dont work out well.

does it have a landscape feature to get everything in focus? On the church shots...you are trying to use a flash that should only be used within 5 or so feet. Try running a higher ISO and no flash.