Salaah

Joining salaahs when travelling

Q: Is it permissible to join the salaahs when a person undertakes a journey and is a musafir? 

Example, you are leaving a country and it is zuhr time so before the flight you join Zuhr and asr? Or you visited a country and you go to a shop and maghrib time sets in so you read maghrib and Isha together? Is this permissible and if not, does one get a sin when they do it?

Performing salaah with impurity on one's body, clothing or salaah area

Q: Is someone who prays 5 times a day consistently with proper wudhu but knowingly and intentionally prays with impurity on the body, clothes or prayer area rejecting the obligation of purification, would this person be considered a disbeliever and be in hell forever? 

Is this person performing wudhu for each salah clearly showing that he is NOT rejecting the obligation of purification?