If a man feels the semen moving when he feels desire without intercourse, and he holds his penis and nothing comes out, then he does not have to do Ghusl according to the majority of scholars. If intercourse takes place, then Ghusl becomes obligatory even if there is no ejaculation.

A wet dream is a means of expending sexual energy for both sexes. A person plays no role in that, rather it happens as a result of human nature and a person will not be held to blame for that. So, wet dreams are something natural, and they cannot be gotten rid of.

When one is in a state of impurity following sexual activity and is unable to do Ghusl because he is sick or it is very cold, he may do Tayammum instead and he does not have to repeat his prayers.

It is not obligatory to do ghusl from janabah when one wants to eat, rather it is Sunnah to do wudu when one wants to eat. This is a matter on which there is consensus among the scholars.

In Islam, it is permissible for the couple to sleep naked. If spouses embrace each other whilst sleeping, this does not necessitate ghusl so long as hugging does not lead to emission of semen or intercourse. For more, please see the detailed answer.

It is permissible for a person, if he is in a state of major impurity, to make Du`a to Allah and remember Him, including the Adhkar before sleeping and others. What is forbidden in a state of major impurity is Dhikr that consists of reciting the Quran, a full verse or more, whether that is read from the Mus-haf or recited by heart.