Hi, thank you so much for the kind words, and especially for the feedback!
Would you mind expanding on what you mean by a separate screen for the Upgrades? To view which upgrades you have installed? Currently you can view those when viewing your deck in the upper-left, but I know it's not ideal and it likely won't be the final way to view them.
I'll have to look into why existing upgrades are being offered up, that's definitely a bug! Right now it should just give you a generic +MaxHP mod if no other upgrades are available, but clearly that's not the case.
As for the game getting stuck after using an ability, that's an old bug that I hoped was finally resolved as of version 0.811, which was released Friday 8/11. Is that the version that you were playing? If so, it's back to the drawing board for that problem. Also if it gets stuck on you again, pressing F8 will allow you to submit a bug report which also grabs the state of all in-game objects and sends it to me, which is a huge help in tracking down bugs!
Thanks again for the interest and the feedback, it's much appreciated :)