(2) Should pubic hairs be cleaned near anus also or only near penis?
بسم الله الرحمن الرحيم
(1) Yes, if the semen discharged with a jerk then ghusl shall be wajib. If it discharged without lust and jerk then ghusl shall not be wajib.
(2) Yes, the pubic hair surrounding anus also should be cleaned.
Allah knows Best!
Darul Uloom Deoband