Hi Srsobieraj,
We highly appreciate your feedback and will work on your suggestions :)
Some things to note, at least until we can release a new update. The spinboxes work with the mouse wheel if the pointer is over the numbers. Pressing Add on creatures in an Entry adds them to the Initiative tracker.
Regarding catching "esc" and "del", this is a really solid feedback. We'll make a pass to try to really make use of the keyboard.