As an European, I find all that Sanders says is possible, particularly about taxes, free education, health care for everyone, etc. The implementation is surely hard, but I don’t think that he thinks that he will do that in 100 days, he is just starting an important process. If not, why is Clinton putting in her agenda more and more points from Sanders’ agenda? Because those things make sense and she knows that. Despite who will be nominated, I hope that they will work together. Don’t forget that in 2008 Clinton was a lot worse in her attack against Obama, than Sanders is know against her, but, after the end of the primaries, they immediately started working together. They will do even this time. 
That said, Sanders’ project is tough and maybe he is a delusional fool, but I don’t think he is dishonest because he is saying these things for all his political life.