Are phone conversations between the two sexes permissible if for consultation, and within the limits of good manners?
                                Such act is impermissible since it renders hearts corrupt, and could lead to forbidden attachment. Allah, The Almighty, Says (What means): "and follow not the footsteps of the devil." [Al-Baqarah/68].
                             
                        
                            
                                
                                What is the ruling on someone who doesn`t perform prayer?
                                All perfect praise be to Allah,The Lord of The Worlds                                                                                                                                                                    Not performing prayer is a major sin, and one who doesn`t pray out of laziness is considered an oft-sinner ;whereas, the one who denies that it is mandatory is considered a disbeliever. And Allah Knows Best.
                             
                        
                            
                                
                                Is it permissible for us to sever ties of kinship if our blood-relatives` gatherings/meetings involve acts of sin?
                                Observing kinship ties is obligatory, and paying your blood-relatives a visit causing their sinful acts to be hindered , then you should do so. However, if their sinful acts continue while you are at their gathering and they didn't respond positively, then observing kinship ties via telephone and the like will suffice in this case. And Allah Knows 
                             
                        
                            
                                
                                If someone bought a car from an interest-based bank and then sold it to another person, does the second person bear any sin if they use the car's price to pay the installments owed to the bank?
                                When the buyer purchased the car, it became their property, and the price became their responsibility. The bank acts as the seller's agent for receiving the payment. Therefore, there is no sin on the second buyer, God willing, as long as the bank does not impose an increase in the amount if a payment is delayed. And Allah The Almighty Knows Best.