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.
My brother works in a conventional bank and gave me one of the gifts distributed to bank employees — what is the ruling on accepting it?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
There is no objection to accepting such gifts, because the physical gift itself does not carry any inherent prohibition — unlike stolen property. Sin does not transfer or extend to the one who receives the gift, for Allah the Almighty says {what means}: "And no bearer of burdens shall bear the burden of another." [Al-Anʿām/164]
The evidence for this is that the Prophet ﷺ himself ate from the food of the Jews, conducted transactions with them, and purchased from them — and it is well known that their wealth was intermingled with ribā. Similarly, the wealth of conventional ribā-based banks is a mixture of the lawful and the unlawful.
Ibn Ḥajar al-Haytamī, may Allah have mercy upon him, states: "It is not forbidden to transact with one whose wealth is predominantly unlawful, nor to eat from it — as al-Nawawī affirmed in al-Majmūʿ." [Tuḥfat al-Muḥtāj, Vol. 9/P.389] And Allah the Almighty knows best.
What is the ruling on one who slept while firmly seated on the ground, regarding nullification of ablution?
The default ruling regarding sleep is that it nullifies ablution. An exception to this is one who slept while firmly seated on the ground; his ablution is not nullified by sleep if he wakes up while still firmly seated on the ground. And Allah the Almighty knows best.
Is it obligatory for someone traveling by plane in the afternoon during Ramadan to fast?
Anyone who intends to travel after dawn must begin the day fasting and continue with the intention of completing their fast, as fasting was obligatory upon them before traveling.
However, if they experience unbearable hardship after starting their journey, they are permitted to break their fast due to that hardship, not merely because of travel. In such a case, they must make up for the missed fast later.