"Bassanio is the sole reason for Antonio's troubles." Do you agree?
No, I do not agree. Bassanio didn't force Antonio to make the deal with Shylock. That was Antonio's decision. I get it, though. They are friends, and Antonio wants to help Bassanio out, but again, Antonio wasn't forced into making the deal.
Second, Shylock isn't the only money lender. Antonio didn't have to make a deal that involved a pound of flesh. Bassanio even warned Antonio against making the deal.
This next one, you may think is a stretch, but I feel it still supports my opinion that Bassanio is not the sole reason for Antonio's troubles. Antonio wouldn't have gotten into financial trouble with Shylock if Antonio's ships hadn't gotten lost at sea. Had they come in, no trouble with Shylock. Bassanio is not the cause of the ships getting lost.