What is the ruling on undoing braids of hair during the ritual bath?
It is not a condition to undo braids if the water reaches all the hair and penetrates to its base. If the water does not reach except by undoing the braids, then it is obligatory to undo them for the water to reach. And Allah the Almighty knows best.
"If the fidyah becomes obligatory upon a pregnant or nursing woman because she broke her fast out of fear for her child, is it obligatory from her own wealth, or from her husband's wealth?"
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
The fidyah (ransom/compensation payment for breaking the fast) is obligatory from the wife's own wealth, and is not obligatory upon the husband unless he voluntarily chooses to pay it on her behalf.
It is stated in Mughnī al-Muḥtāj (Vol.2/P.174): "If the two [the pregnant woman and the nursing mother] fear for the child alone — such as a pregnant woman fearing miscarriage, or a nursing mother fearing that her milk supply would decrease, thereby endangering the child — then both the qaḍā' (making up the missed fast) and the fidyah become obligatory upon them, to be paid from their own wealth." And Allah, the Exalted, knows best.
If someone fasts on the White Days with the intention of making up for missed fasts (qada), will they receive the reward for both voluntary and obligatory fasting?
Making up missed obligatory fasts (qada) is mandatory, and the intention for qada must be specified.
If a person makes up their missed Ramadan fasts on the White Days, they must intend qada, but they may also intend to fast the White Days, and Allah willing, they will receive the reward for both.
This is similar to entering a mosque and praying an obligatory prayer, where the person also earns the reward of Tahiyyat al-Masjid (greeting the mosque) if they intend both.
● If the person missed their fasts due to a valid excuse, they may wait and fast on the White Days.
● However, if they missed the fasts without a valid excuse, they must make up the fasts immediately and should not delay them until the White Days.
Should a person feel pleased, or have a virtuous vision after offering Istikhara (guidance prayer) in order to do what he/she had offered it for?
The result of the Istikhaarah is not necessarily that a person sees something (in his dream), or feels pleased, but the most important result of the Istikhaarah is whether a person is enabled to do a given matter or not.