Okay @dancemasterglenn, that’s a long edit you’ve taken your time on so let me do the same! 
Clear Timeline - this is at the top for positioning concerns, keeping it there means that you have a “Remove” and a “Remove All” right next to each other, putting at the bottom away from the other editing buttons (add and remove) means a user would have to go searching for it, where it is now shows it’s immediately available.
Unmuting is not possible as this is a game centric setting.
Changing the helpful sounds would involve a new options window which is fine but you also need to remember that these sounds are specifically synced to be in time to the 60th of a second you need to be accurate.
Repeat mode has no cap so there’s really no need to put an infinite button on it, you can simply stop it by depressing the Play button again, I stress tested the combo trainer once by making it play back 10000 times over night, it hadn’t finished when I had woken up so I think it’s fine. As well as that there is no need to put a pause in between the loops as you can easily add a pause at the end of the timeline with an empty timeline item adding it as a separate feature just creates more for a user to track and also to get wrong.
For the lead in sound again you could add an empty timeline item and enable the sound to “start” the combo for timings sake, don’t forget this is a training tool, it’s not meant to be “epic” - but practical 
The enable/disable sounds for the whole timeline is a good one that we need to put in for ease but for the volume just use Windows Mixer, that’s what it’s there for.
The clicking on an input entry being difficult is due to a known issue with making custom list controls in WPF and being unable to click on the child controls to activate a list item, we’re working on the recommended work around at the moment.
Alternating between dark and light was overwhelmingly disliked by our user-base in the closed beta and had little to no positive feedback, it makes the graphics look too noisy and disrupts the visual information from the multi colours in the button displays for punches and kicks. I might however try a small separator line that is faded to achieve the separation but keep the clarity of design.
Tooltips are being worked on for everything in the program so these will more than likely be updated alongside!
Lastly thanks so much for the detailed feedback, it’s a relief to get it when we can as it’s the best way to find what needs improving so thanks for taking the time to give it!
