the green slime on the soil is kind of common. unless you really, really, want to repot the plant, i would just scrape off the slime, and put a little peat in it's place. if you have any live lfs, that make a nice top dressing too.
remember that, if you are going to sterilize the old soil with boiling water, if you use tap water, any minerals that are in it could build up in the soil.
peace,
tech...