Clause stating that if the buyer defaults on an installment, the entire outstanding balance becomes immediately due

Q: If a person purchases an item on a payment plan, agreeing to pay the price in fixed monthly installments over a set period, and the contract includes a clause stating that if the buyer defaults on any single installment, then the entire outstanding balance becomes immediately due and payable. Is such a condition valid and permissible?

Correcting the direction of the qiblah in the masjid

Q: In my masjid, the qiblah is off by a bit. In between 35 - 43°. (Closer to 40° in most apps) 

They are getting new carpets fitted insha Allah. However, the committee are disputing on whether to face it to the qibla or keep it as it is. They will lose a few musalla spaces if they angle the carpets and it will make the carpets not match the building which they don't want. 

I've said, although the salaahs may be valid, it would be best to angle it and go closer to the qiblah, preferably within 20°. Could you give a final answer into the matter?