I may have been going at Si the wrong way, although I'm still unsure about the way to approach it. I've been describing +Si as positive sensations and -Si as negative sensations. I am almost certain that -Si tends to deal with a strong hygiene. Gulenko describes +Si and -Si as proactive ("+"): stabile comfort, habitual sensations
reactive ("-"): thrill, different sensations, change in physical state. While there is probably some correctness to this, I feel that this has a lot to do with Se instead of Si. I believe that along with many other things Se encompasses whether or not a person would prefer to have "wild and crazy" fun or have a habitual lifestyle. I believe that Gulenko is somewhat incorrect with how he broke it down. For instance ENFps, INFjs, INTps, and ENTjs are probably huge thrill seekers. They probably like to skydive or chase a tornado or something, something drastic. -Se prefers the safe habitual environment. They don't like to do anything too extreme in lifestyle. Where does this leave Si though. +Si has something to do with euphoria, I can say that for certain. -Si has something to do with hygiene. I've been thinking about how Fe and Fi works and how whats external is the opposite of whats internal(it should work that way for all functions, although with the descriptions its hard to see). Because of this I'm thinking that Si is the same as Se except for introversion extraversion. Maybe -Si is careful maintenance of the body(meaning they would take good care of hygiene and stuff), and +Si is about unique sensations to the body. This would mean that types like INTjs with a +Si agenda would prefer to explore their bodies and try to do things to make it feel exceptional, and -Si types like INTps would take careful care of their bodies and not do anything overly dramatic.