I think it would be convenient for there to be some visual effect or marker to distinguish summoned monsters from monsters in the location deck. They have different rules, they have different consequences, and having a reminder about what type of card you are facing would help out.

Totally agree.

Since this is a digital game, could the text actually change on the cards?

Summoned Bandit.

And remove the text that says when defeated you may close this location.

Why keep that on there when you don't have to, just make it a different card. 

While we are at it, I would love if there was something that told me if I needed to defeat a monster or not. I'm always worried that I'll hit Merisiel's evade without thinking and fail to defeat a nasty barrier.

I Totally agree. I am a quite often confused, if the monster is summoned or "real" in this digital version. 

Maybe a semi transparent version, different color, magical halo around the card. Extra game text or adding new trait "Summoned" to the cards that has been summoned.

Good idea, I'll submit this suggestion for ya!