These questions came out of a recent discussion between friends and would really appreciate if you can provide answers. The text 'You' in the questions refer to one friend questioning the other.
1) Were women part of the Shoorah, decision making body, etc., in the time of Rasoolullaah sallallaahu alayhi wa sallam's time, in the Sahaaba's time, in the Tabieen's time, in the Tabia' Tabeen's time, can you relate any incidents in history where women were in the decision making body or the Shoorah? If not then why is the need now?
2) You say having sister's on the board is very much a practical issue rather than a religious issue? There is no such thing as a practical issue in Islam, every issue of a Muslim is religious, and its part of his/her Deen and it needs to be addressed in the realms of the Islamic Sharee'ah? What are such issues that any women can not relay through her Mahram men (husband, brother, father, etc.) to the Shoorah? What issues can not be relayed to the all men Shoorah through the women and they can not the be discussed as used to happen in the time of the Prophet, sallallaahu alayhi wa sallam, and his Sahaaba?
3) Third question is that you say we need to distinguish between the culture of Islam and the religion of Islam? There is no such thing as culture of Islam. There is only the religion of Islam and we all need to abide by it.
Our issues and problems need to be resolved by it. If there is a need to be fulfilled it needs to be fulfilled by staying in the bounds of the Sharee'ah, by adhering to the principles and ways adopted by the Prophet, sallallaahu alayhi wa sallam, and his Sahaaba, not use our interpretation of things.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

In Islam a woman has a great status. Islam honoured her as a mother, a wife and as daughter, and put her in a honourable position and protected her dignity. There is no religion which honoured the woman like Islam has done.

As regards seeking the consultation of women, it is known from the guidance of the Prophet that he used to consult them in some general and private matters. It is confirmed that the Prophet sought the consultation of Um Salamah on the day of Al-Hudaybiyyah. He acted according to her opinion and he achieved what he wanted. [Al-Bukhari] It is also confirmed that the Prophet said: "A widow should not be married off except if she agrees and a virgin woman should not be married off unless she gives her consent." [Al-Bukhari and Muslim] Moreover, it is reported that 'Umar asked his daughter Safiyyah : "What is the maximum period for which a woman can tolerate the absence of her husband from her?" She replied: “Six or four months”. 'Umar then said: “I will not keep the soldiers more than this period.” [Al-Bayhaqi]

There is a difference between seeking the view of the woman in a manner that does not contradict morals, and her attending the meetings with men in a manner that hinders her primary task in this life, which is cultivating the future generations (i.e. children). Allaah created a woman upon naturally being patient and enduring, and made her able to fulfil this task which men are not able to fulfil. Therefore, the matter is not that of discrimination between the man and the woman, but it is giving each one his task that suits him/her and suits the characteristics that Allaah has created in each one of them. So whoever wants to divide the obligations and tasks equally between the man and the woman, he has first to equalize in relation to their creation, and he will never be able to do so. Therefore, he should leave the matter to Allaah, Who is the Wise Creator. It is the one who creates, who is able to legislate. Allaah Says (which means): {Unquestionably, His is the creation and the command; blessed is Allaah, Lord of the worlds.}[Quran 7:54].

If there is a need of seeking the consultation of a woman, it is not a condition that her Mahram (a non-marriageable relative) be present. It is enough to avoid being in seclusion with her mixing between men and women or being in a situation of doubt.

As regards saying that religion has nothing to do with the issue of women participating in deputy membership committees, then this is not a sound opinion. The reference for Muslims in all their affairs in this life should be the religion of Allaah. Allaah Says (what means): {And in anything over which you disagree — its ruling is [to be referred] to Allaah.}[Quran 42:10]. Allaah further Says (what means): {But no, by your Lord, they will not [truly] believe until they make you, [O Muhammad ], judge concerning that over which they dispute among themselves and then find within themselves no discomfort from what you have judged and submit in [full, willing] submission.}[Quran 4:65].

With regard to the Islamic culture, this is a new term and it is not known that our righteous predecessors used it, but if its meaning is acceptable, then there is no harm in using it, Inshaa' Allaah; like intending to mean by Islamic culture, the principles, teachings and rulings of Islam, and so forth. However, it is not acceptable to consider Islamic culture something other than religion.

Allaah Knows best.