Thanks for playing! Your point about inputs resulting in nothing is a huge oversight on my part, you're right that it happens when there's no move associated with a direction. Neutral inputs are too strict. Beyond that, would you mind specifically noting when you felt like inputs were getting dropped? I recently reworked the input buffer so it's worth investigating.
As far as normal enemies being tough, that's by design. Normal beat em' ups build their challenge around crowd control and dealing with hordes of enemies, the natural consequence is feeling powerful mowing down a ton of dudes. This game aims to make encounters micro fighting game matches where understanding your tools and how they relate to your opponent's tools is the reward.