بسم الله الرحمن الرحيم
(1) It is lawful to establish marital relationship during the night of Ramadan with wife like other days. However, intercourse is not lawful in the state of fasting. It shall nullify the fast and he shall have to offer qaza and kaffarah. Likewise, one should avoid the activities which lead to intercourse so that it does not cause the breaking of his fast.
(2) If the liquid was discharged in less quantity and it did not cause exhaustion then it is madhi; it shall break the wudhu and the place shall become impure where it is smeared. However it does not make ghusl wajib.
Allah knows Best!
Darul Uloom Deoband