Many forms ending in -ed stem from full past participles, e.g. scared, angered, annoyed, pleased, destroyed, fixed, touched, relaxed, etc. These forms actually line up somewhere between adjectives and full past passive participles. The one form may be more participle-like than adjective-like, and the next may be more adjective-like than participle-like. There is a participle-to-adjective continuum of a sort, whereby a given form ending in -ed appears somewhere on the continuum.
Many forms ending in -ing stem from present participles, e.g. pleasing, annoying, touching, relaxing, etc. These forms line up somewhere between adjectives and full present active participles. The one form may be more participle-like than adjective-like, and the next may be more adjective-like than participle-like. Thus there is also a present-participle-to-adjective continuum, whereby a given form ending in -ing appears somewhere on the continuum.
Present participles express active meaning, whereas as past participles often express passive meaning. There is therefore a clear difference between the forms pleasing and pleased, the former indicating active meaning associated with a cause and the latter indicating passive meaning associated with a patient.
Forms such as scary, angry, touchy, etc. are simply adjectives. Whether or not they derived from verbs is not clear (to me), although they seem more like active participles than like passive participles, since the meaning they express is associated with a cause or an agent.