It is not permissible to shave the beard, and this is as an edict, not a precautionary ruling, so one cannot refer to somebody else in this regard. It is permissible to shave the moustache.
The signs of semen are sexual excitement, forceful ejaculation and tepidity. If none of these signs is present - for a healthy human - then the discharge will not be considered to be semen. If the man was asleep during the discharge, then the two signs of sexual excitement and forceful ejaculation are sufficient to deem the discharged substance to be semen and najis. For somebody who is ill, such ejaculation with merely sexual excitement will be sufficient to regard it as semen.
This topic entails a detailed discussion, but in summary Allah said: “And if, when they had wronged themselves, they had but come unto thee and asked forgiveness of Allah, and asked forgiveness of the messenger, they would have found Allah Forgiving, Merciful” (4:64). It is clear that the intercession of the Prophet (peace be upon him and his progeny) is one of the causes of divine mercy and forgiveness, and there is no evidence that this is limited to his life, especially with the traditions narrated from him that indicate that he replies to our salutations and greetings to him after his death; so just as salutations reach him after his death, so do our requests for his intercession.
There is no doubt that the presence of the Imam (peace be upon him) has its blessings and great effects on the welfare of mankind other than his role as the guide of people. Many narrations indicate such existence of blessings, like what is reported in some phrases of the Ziyarat al-Jami’ah.