I completely agree with you, especially on the blocking part.
Unbinding finishers from normal melee attacks would also STILL be a thing that needs to happen. Finishers themselves are so extremely bad that you would never want to use them except for frames specifically build for them like Ash and even he uses an ability to execute those finishers. Warframe seems to habe become a somewaht faster game over the years and finishers are, as they are right now, an element of the slower past.
Quick example: Pulling together some enemies with Nidus's  would be an awesome setup to beat them all down with awesome melee gleave, right? Ouh wait, yeah you need to strafe around the ball of enemies trying to avoid executing finishers on one mob only each time.
Next one: Loki should be able to profit from melee stealth dmg bonus, right? Ouh wait, alone in a mission and you're also constantly finishing unintentionally.
Please do something about this age old problem, DE. Being stuck in an animation that, in most cases, is way too long, unintentionally executed and more frustration seeing it happen than awesome doesn't fit your even now increasingly awesome game.