Missing Jumuah Salaah due to college classes

Q: It is often said that, for a man in particular, missing 3 Jummah Salahs in a row eliminates him from deen. My question is that living in a foreign country, if someone misses them because there is no Mosque within miles, and the time of Salah clashes with the man's college classes. What does the Shari'ah say in these circumstances? In the namaz, is it not permissible for one to say Bismillah after Surah Fatiha (Before starting the second surah)?

Omitting one's Salaah and performing it as qaza due to one's job

Q: I recite quaran daily in the morning without fail. Also I had started salat but unfortunately I can not perform five time salaat on time because my job is like that. So whatever time of salaat I get, I perform it. Like I came early home so I perform magrib and isha. So my question is that how can I perform Salaah on it's proper time or else I have to perform kaza namaz.