Some help with cleaner options

"Cleaner" function: Which items should I safely have checked? I have attached a screenshot of what I dared check on my own. I don't want to remove anything that might cause me problems. Can someone advise?

post-47040-0-28051800-1300741320_thumb.jpg

The default settings are probably alright for a start. In your pic (is this the default?) I have the same except that Autocomplete Form History is unchecked.