Thank you so much for your comment! you've touched on a lot of things I've noticed and am working on and some I hadn't at all noticed, this is very very helpful to me!
I planned on adding more movement options with cards but I will definitely add more defense options that don't require cards or meter, especially directional airdodges. Also nice that you brought up card bookmarking which is also planned.
A lot is being worked on but will release an update soon to address most of this, so I do hope you keep playing. Training mode is definitely planned but will take a bit to implement sadly.