Thanks for taking the time to play!
We've never ran into the issue you mentioned first, really odd. Some cards require tributes to be played, maybe you only drew those and I didn't explain the tributing mechanic in the game so its possible (cards with a number in the top left corner require a tribute of X monsters, so if you have none you cant do anything)
Fair point on the third part as well, I did feel it was too fast and was implementing a system where you can speed up or slow down animations and stuff but didn't have time to finish it unfortunately. If I was to keep working on the game, i'd for sure add that along with some on hover details popping up and better explanation of keywords etc. but all we have now is a card game framework essentially