Consent occurs when one person voluntarily agrees to the proposal or desires of another. It is a term of common speech, but may have more specific definitions in such fields as the law, medicine, research, and sexual relationships. Types of consent include implied consent, expressed consent, informed consent and unanimous consent.
Harming people is not allowed in Islam. If it does not harm them now or in the future and you are sure that they will never object on it, then it becomes permissible.
We know that the one wajib thing a wife must observe towards her husband is "tamkīn", which means sexual availability.
Of course, this does not mean the husband can "force" himself onto his wife, or what is known in today's society as "marital rape". If this was the case, and the husband forces himself on the wife, then in reality their marriage has already failed and fallen apart.
A healthy husband/wife relationship also depends on their physical attraction towards each other and sexually satisfying each other. This is why the wife should aim towards sexually satisfying her husband, and the husband should also cater to his wife's needs.
Both also need to be considerate of the physical, mental and emotional state of each other. If she or is sick, or not in the mood, or upset for some reason, or tired, or anything else, and it's not an ongoing excuse, then they should be considerate and respect their spouse. Be patient, be understanding, think beyond just sexual satisfaction, and build the relationship between you and your spouse.
Of course, it should never be to humiliate or extract revenge or get back at the spouse. This would be sinful and haram.
Intimacy has its value when both sides are enjoying, and hence both the husband and wife should aim towards living together with a healthy intimate life and also adhere to what our Islamic akhlaq and laws wants from us.
With prayers for your success.
Yes, the Nikah is valid because he was meant by whatever name was used.
You should check this with your marja because some scholars would state that if the intercourse was illegitimate such as the girl committing zina, then she would still count as a virgin and father's permission would be needed. If she however lost her virginity in a legitimate type of way then permission isn't needed.
May Allah grant you success
Thank you for your question. God didn't take the concent of His creation before creating it. Perhaps you are referring to His pact with humans when they responded positively to Him being their Lord? If that is the case then this is one of the specifics found in the Quran and once the Quran has been established as being the book of guidance from God then there is no need to prove each and every specific. Further, this issue can be interpreted as the natural disposition of the human to seek God. If the atheist is not willing to accept that they have that disposition, that doesn't matter as this position is a theological one and so there is no need to convince an atheist as long as the issue is consistent within the theological framework.
As for the second question, God created mankind out of His Mercy and that included the creation of vicegerents on the earth. The necessity of trial is due to the nature of reward which is given for praiseworthy action. There is no praiseworthy action if it hasn't really taken place or if it is forced. Therefore a human has to be free to act and this is the meaning of trial.
May you always be successful
If a Muslim woman is in need of marriage and has found a person religiously suitable for her, and there is no other man to propose her while her father/wali unreasonably doesn't consent to the marriage, she can refer the case to an Islamic authority and marry without her father/wali's consent. Some scholars hold the opinion that a "legally mature woman" (rashidah) is not in need of her father/wali's consent although such view is not agreed upon.
With prayers for your success.