Can the hairline from the temple up be trimmed to be squared? With trimmers to emphasize/detail the natural shape? Not bangs or to cut into it but to be trimmed and lined along this area? No blade only electric trimmers with no guard. The same with the sideburns can they be squared off at the bottom if low enough? I now only cut my own hair with a #5 guard and leave the hairline alone. It does not have the most professional look, I do not shave but again looks bushy does not have a clean look.
ב"ה Shalom The Shulchan Aruch (Yoreh De'ah 181 ) says that "Pe'ot Harosh", are not to be shaved by a razor or by scissors like a razor, which means that the blade comes in contact with the flesh and leaves no hair at all(ביאור הלכה סי' רנא, קצוש"ע קע:א) Therefore cutting the with scissors or trimmers which don't allow the blade to be so close to the skin are permitted. ( שו"ת חתם סופר או"ח סי' קנד, בחכמת אדם שער איסור והיתר כלל פט, טז, שאילת שלמה חלק א : רסז, מראה הבזק ט:יט) ) Peot Harosh according to the Shulchan Aruch extend to area parallel to the bottom of the ear. All the best שנה טובה ומבורכת