Is it permissible for a wife to leave her house without asking her husband?
It is impermissible for the wife to leave her house without asking her husband except for a sound reason.
Am I permitted to perform more than a prayer within single ablution?
All perfect praise be to Allah, The Lord of The Worlds, and may His Peace and Blessings be upon our Prophet Muhammad and upon all of his family and companions.
You are permitted to pray as many as you could within one ablution and to recite Quran so long as your ablution isn't nullified. And Allah Knows Best.
Someone asked me to pay off his debt on his behalf as a loan, without any compensation. When I went to the creditor, he told me that if I paid the full amount at once, rather than in installments, he would give me a certain discount. Is this permissible? And if he applies the discount, to whom does the deducted amount belong?
If part of the debt is paid and the creditor forgives the remaining amount, the waiver is valid, and the remaining debt is no longer the responsibility of the original debtor. The person who paid the debt on behalf of another has no right to claim any portion of the original debt. And Allah Knows Best.
Is the Central Bank of Jordan considered of the Commercial Banks?
Yes, since the Central Bank involves with usury.