I wasn't able to reproduce this bug where you removed the third hero and lost it's items, they should go to the inventory, please check if you had any filters enabled at the bottom, just left of the inventory :)
Thanks for all the feedback, it really means a lot, I will try to implement fixes for disconnected dungeons asap, I will also try to balance monsters/dungeons vs heroes, it can be quite rough, I also implemented a rudimentary stat screen for heroes
For the abilities, you need to click on the button underneath the ability where the cost is shown, They seem to work for me, if you still have troubles please let me know
I've added in the base hp and base damage values to display in stats and be used when raiding. I also made most monsters easier for now, i will do a playtest myself and balance them further when I gathered enough info, please reload the game in your browser to start having these changes applied :)