The combat system needs some tweaks, fixes and polishing but I like the general concept and for me it works quite well. Those who are unable to riposte, dodge and block are either experiencing a bug or need more practice because I can do all of the above without a problem. I have beaten all three enemies in the training fights several times.
I think Q is a bad button for blocking because it makes it difficult to move during combat, maybe spacebar would be better, no need for jumping in combat anyway.
It looks like feints are related to skill, had no problem to use them against easy and mid, was unable to use them against the hard enemy.
If you want to get rid of target lock simply press sprint.
Combos are too difficult in my opinion, not the combinations but the timing.
You don't need to block in the correct direction if you want to do a riposte, it's just about timing and immediate counter attack. Also make sure to have enough stamina to be able to attack several times once you breached enemy defenses.
Don't blame the game because you didn't understand the combat system / train enough. Make sure to learn how the different techniques work, keep the correct distance and watch your stamina. Make sure that you know what you want to do before you get attacked, decide if you want to dodge, block or riposte and prepare accodringly.