Topic: Tag Implication: sex_toy_fellatio -> fellatio

4, 5, 6 I'd give a definite +1: no strapon fellatio without a strapon, no sex toy fellateo without a sex toy, and a strapon is a sex toy. 3 is a -1, see eggplants linked post. Other two I don't know.
Oh and btw, if you surround a tag with [[double brackets]] you link to the tags wiki, practical in tag discussions. Same goes for {{curly brackets}} to tag search.

Updated by anonymous