Is it permissible for the young woman to turn the suitor down if she had no feelings for him?
Yes, it is permissible for her to do so.
What is the ruling on a second congregation [being formed] in the mosque?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
It is disliked to deliberately seek to establish a second congregation in a mosque that is not one frequented by transient passersby — such as a neighborhood mosque with a regular, appointed imam — unless permission is granted by that imam, since doing so implies criticism and an affront to him. However, if the mosque is one frequented by transient passersby — such as mosques located in marketplaces — then a second or even third congregation is permissible there, whether or not it has a regular, appointed imam, and whether or not that imam gives his permission. This is because such mosques experience a continuous flow of people coming and going, so no implication of criticism toward the imam is perceived in the formation of multiple congregations in that setting. And Allah, the Exalted, knows best.
Is it permissible for the wife to give the Zakah (obligatory charity) of her money to her poor husband?
Yes, it is permissible for the wife to give from the Zakah of her money to her poor husband. And Allah Knows Best.
A person who has recently embraced Islam is afraid of undergoing circumcision (khitān) — what should he do?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
If this person would be harmed by undergoing circumcision, based on the assessment of a trustworthy physician, then he is not obligated to undergo it. However, if the matter is simply a fear of the procedure itself, then it may be postponed until he feels at ease and settled about it, provided this does not lead him to become averse to Islam — while still taking care to remove any impurity from the concealed area [beneath the foreskin]. And Allah, the Exalted, knows best.