Rating issues
Most of the violence depicted is sustained and is limited to fist fights. Each hit causes a recoil response from the character which is accompanied by some blood splatter. At the conclusion of the fight, the defeated character falls to the floor and remains in view.
There is the infrequent use of the sexual expletive ‘fuck’
Regarding the glamorisation of crime, there are many incidents in which a crime is proposed, carried out and tangible benefit is derived from the crime. An example is the theft of champagne from a rival gang, the intended purpose being to supply a celebration in honour of the Peaky Blinders. Much comment is made at the event of how they have gained respect amongst the attendees being able to drink expensive champagne.
Other issues
There are references to Opium but no depictions of the drug being taken / used.