Note: These are my personal opinions, I'm not looking for conflict.
Not enough eps, I think with this kind of escalation in plot it should of had 12, at the very least, it would have left far more time to develop Angel Dusts character.
It had a three season story squeezed into 8 eps it was mad, if the battle had taken place three seasons in, the reveal of Vaggie being an angel, the fear of war with Heaven and the death of Sir Pentious would have meant so much more to the audience.
To ethicise Angel's deeply ingrained hyper sexual behaviour, it should, in my mind have been shown more so how uncomfortable he makes the other staff especially Husk.
Charlie got over Vaggie being an angel far to soon, imagine the emotional conflict if they had actually broken up, or atleast separated, If Charlie have had an episode or two of her going through the motions of forgiveness, Vaggie being cast out the hotel in shame Alastor using it as a means of emotional manipulation to grow closer to her, praying on her vulnerability and THEN he swoops in and makes the deal, showing again Alasor is a grifter and will take advantage of someone if he feel's he can benefit.
The Friendship between Lute and Adam should have had atleast three scenes dedicated to it, they are bad people but to make then good characters in the sense that they have depth would have been great for the audience, for atleast some emotional reaction for Lute, yes Adam is a twat who deserved to die, but just a pang of sadness for Lute would have been great.
too much swearing, it's excessive and cheesy, instead of Alastor saying ''Im about to end your fucking life'' he could have just said ''I am about to end your LIFE" with a deep growling kinda thing on 'life' of instead of Vaggie saying ''Shitass'' (A terrible sweat word) she could have just not said that it didn't add any enthesis on her conversation with Alasor.