I wanted to learn whether all kinds of sexual activities done in the name of foreplay are allowed. Should foreplay not have some restrictions in the name of purity and decency? Is it possible for a wife to refuse some foreplay activities? Would it be sin for her? Would it be considered deviation from her sexual duty towards husband?
Does husband have a right to have sexual relationship, including all kind of foreplays, and wife cannot refuse? If wife gives permission for normal intercourse but not for some kind of foreplays, what is the ruling of shar'iah here? Does wife have no likes or dislikes about foreplay? Has she to surrender if husband is doing anything except menstrual or anal sex?
We believe that the basic purpose of the religion is to guide humans to purify themselves intellectually, morally and physically. Marriage itself is an institution that guards us from being carried away and indulgence in unrestricted sexual behavior. Wives and husband are, according to the Qur'an, garments to each others. It implies that they can satisfy their sexual desires in the way God has directed them through the nature and through the revelations. As you said there are two prohibitions in the Shari'ah. Intercourse during menstrual cycle is explicitly forbidden. Anal sex however is considered to be prohibited because God has said that men should approach women through the path God has told them. Now this is not told in the revelation. Rather the reference is towards the guidance provided in human nature corresponding to the natural make up of the human body.
This very argument can be extended to oral sex. By oral sex I mean cunnilingus and fellatio. We cannot claim that they are as clearly prohibited as adultery (zina) or even anal intercourse but we can see that mouth has been created by God for other purposes including remembering the name of God and reciting the words of God. A believer must refrain from polluting it if he has an intention to recite the word of God and remember and exalt Him with the same tongue.
If a believing wife thinks that it is not allowable for her to do these acts and she refuses to indulge in these activities it would not be a sin on her part. But there is a difference of opinion and one should not go as far as sacrificing the marriage if the husband is strict and demands that with great stress. However, she should talk to him wisely and let him know that what he demands from her is abhorrent to her and that she feels her religion does not allow it.