coming across such an distinction here: how, if, should such be understood in Dynamic context?
Can deeds ever be an input phenomena?
Yes, of course. In the following sutta, we read that a warrior who strives and exerts himself in battle with the intention to kill others, reinforces violent tendencies. It may also cause psychological trauma, according to the psychology article that comes after that.
When a warrior strives & exerts himself in battle, his mind is already seized, debased, & misdirected by the thought: 'May these beings be struck down or slaughtered or annihilated or destroyed. May they not exist.' If others then strike him down & slay him while he is thus striving & exerting himself in battle, then with the breakup of the body, after death, he is reborn in the hell called the realm of those slain in battle. But if he holds such a view as this: 'When a warrior strives & exerts himself in battle, if others then strike him down & slay him while he is striving & exerting himself in battle, then with the breakup of the body, after death, he is reborn in the company of devas slain in battle,' that is his wrong view. Now, there are two destinations for a person with wrong view, I tell you: either hell or the animal womb."
Robert T. Muller, a professor of psychology, wrote in the article "Death Becomes Us: The Psychological Trauma of Killing" (Feb 21, 2014):
Killing is often misrepresented in film as far easier than it is. In reality, the “duty” is mentally taxing, leaving most soldiers physically ill in the moment and often haunted by nightmares for a lifetime. Being responsible for ending the life of another human is a significant source of trauma ...
Apart from about two percent of individuals classified as “psychopaths,” who, because of deeply rooted personality flaws are unphased by the act of killing, most soldiers are unprepared for the task of ending the life of another human being. Many veterans report that ending even one life is enough to haunt them with painful memories and sometimes flashbacks.
Soldiers who have engaged in close combat are left with a much higher likelihood of developing post traumatic stress disorder then their counterparts who did not.
This is supported by the following sutta quote:
Anyone who kills living creatures creates dangers and threats both in the present life and in lives to come, and experiences mental pain and sadness. Anyone who refrains from killing living creatures creates no dangers and threats either in the present life or in lives to come, and doesn’t experience mental pain and sadness. So that danger and threat is quelled for anyone who refrains from killing living creatures.
AN 10.92 also explains how the five precepts represent deeds that help purify the mind.