Wow, this really has you "bugged"!!!
Sorry, I couldn't resist! (Well, I could have but just didn't!)
About your spider situation - My Godmother, who is the Great Poobah of all things domestic, has never had a problem with spiders. What she does is takes a piece of terry towel and wets it in a mixture of vinegar and water and then wipes down the corners of her rooms and along the edges where the ceiling meets the walls. She even runs it over the ceiling, too. She wraps the piece of towel around a swiffer mop so it's very lightweight and then just cruises along wiping down the corners and ceilings. It takes less than 5 minutes a room. I think she does this about every week or two and she's never had a problem with spiders.
You might want to put some vinegar in the water you use to mop floors, too. Anything to discourage the invasion!
Hope this helps!