as-salamu alaykee
as far your first question, you can refer to What is it permissible for a man to do with his wife during the day in Ramadaan?
as far second, you have to make sure that you do ghusl before the sun rises so that you can offer your Fajr salah on time. There is nothing wrong if you delay the ghusl and do it after the sahur (sahri).
Allahu A’lam