You're definitely spot on about that hover-highlight. That's something I also noticed and am planning to remedy. The pop-up window not working as well on the edges is also known, but I figured since the edges are mostly not the ideal locations for towers anyway, I can leave it for now in the game jam release. I'm not sure what you mean with the turret firing at the closest dice, they should always fire at the dice which is the furthest along the path. Maybe you encountered a bug there, I'll look into it!
I'm really glad to hear you enjoyed it so much though, even though tower defense isn't your go-to genre. Thanks for playing and thanks for your insightful comment!