I'll honestly say I'm somewhat underwhelmed with machetes and especially flurry. I think it works out fine in theory but in practice anything below 85% to hit tends to fuck you over much sooner rather than later. God forbid you have 50% chance to hit on something, then you are well and truly fucked, don't even attempt to flurry, it's not worth it. Well, or savescum for it to work. As it turns out though, more difficult enemies tend to give you a lower chance to hit, and when (not if, when) your flurry fails, you are stuck next to a dangerous enemy in melee range. You're not very much in a position to escape. I'm not sure whether I'll abandon the build yet, but for now my impression is flurry/machetes are only effective for someone who is willing to savescum their way through everything, or they might only really work if you also have a reliable way to keep consistently stunning enemies, raising your chance to hit them.
Also, about parry/riposte, which I haven't tested yet, 2 feats is severely expensive. I'm guessing for now it might not really be worth it and there will always be dozens of other things you can do with 2 feats instead of taking parry/riposte.