Wednesday Wordage falling from respectability edition

I guess if you stand too close to somebody for too long, you might be mistaken for them, despite being completely unrelated.  Some words have actually gotten people--politicians, teachers, etc--into trouble or fired, simply because the words stood to close to bad words in the dictionary. 

Here's some pairs of definitions--one innocent, one less savory.  Guess the troublesome words.

1.  Stingy, derived from OE word for "miser"/ socially unacceptable word for person of African ancestry.

2.  Educational / prone to molesting children

3.  A word that sounds similar to another word / a person attracted to members of the same sex

4.  A problem that gets worse, and more inescapable the more you try to deal with it, derived from elements in African and/or Native American folklore / socially unacceptable word for person of African ancestry.

Highlight for answers, with references:
1.  Niggardly.  (a wikipedia list)
2.  Pedagogical.  (possibly an urban legend...)
3.  Homophone.  (a newspaper report)
4.  Tar baby. (an editorial)

It's sad to see a word, through no fault of its own, fall into disrepute and disfavor.  Ultimately, though, I have to own that the language is not what I want, or what is in the dictionary, but what people speak.  As always, I'd be amused to see any of your contributions