Combining Sentences

Emily was a gifted painter but she never studied art. [What's the error?]

The newest tablet is so light, it's had to believe what it can do. [What's the error?]

It rained for hours on Saturday; finally, the rain stopped Sunday morning. [Is this sentence correct?]

We can go to the movie at the mutliplex, or we can play games at the arcade. [Is this sentence correct?]

Which one is NOT part of the FANBOYS acronym?

You never keep secrets, therefore most people don't trust you. [Is this correct?]

He liked to run, and to swim. [Is this correct?]

Jo drove, so Mike was in charge of the radio. [How is this combined?]

My bus commute to college is long; however, it gives me time to study. [How is this combined?]

My car is making noises; I should get it checked out. [How is this combined?]