Do you want critique on the fluff, or are you just sharing? Like, the full Liber treatment?
Heh I'm gonna bite anyway

...
The Emperor’s warbastards were formed as a direct command of the high lords of Terra in an attempt to create a chapter of marines for almost exclusive use in faith based conflicts and suppression of social movements/heresies within the Imperium.

Uhh why select the BA gene stock for this? we are a lil off kilter, and All Loyalist marines take part in averting heresies and as for social Movements that is why we have Arbities e.g Space cops that do this sort of thing.
While most marines follow the cult of their original legion, the war bastards were not informed of the gene-seed used to create them, and as such have no knowledge of their original history.
This just smacks of lazy writing
They follow and worship the emperor as a divine being exclusively as dictated by the imperial cult.
Uhh you know those guys I think they were called the Word Bearers they did this and look where they ended up In fact Marines are frowned upon looking at the Emperor as a God rather than a example of Humanity at its pinnacle.
They are a new chapter, having only been active in combat for 200 or so years. They are recruited entirely from the Necromundan 412th legion, or the redemptionist crusade – a guard regiment created largely to thin down numbers of violent religious fanatics prowling the hives of Necromunda by press-ganging them and then throwing them at the guns of heretics.
Marines do not recruit from IG worlds and uhh redemptionists are you know a Hive Gang on Necromunda and are the whole religious fanatics that Prowl the Hive of Necromunda also they do not need a IG Pressence on Munda because again they have Arbities.
This rather limited method of recruitment and the extreme (even for marine standards) ritual and religious duties leave them little more than manic genocidal berserkers, easily on par with the famed flesh tearers for sheer brutality.
Pffftttt there are comments I "could Make" But won't But sorry newbie but your Marines are not going to hold a candle too the established Blood shedders.
The combat doctrine of the warbastards is one of extreme and unlimited anti-secessionist warfare. As they are often fighting in urban areas they have a very skewed organization, relying heavily on assault troops, and their squads are almost exclusively armed with flamers. They use a limited supply of redeemer-class landraiders, rhinos and whirlwinds as their primary vehicles.
So far this is the best part BUT this is seen pretty much everytime somebody in LA wants to use BA codex for their Marines and almost a copy pasta job..
Perhaps the most notorious battle in the chapters history, and the one that signaled the utter failure of the project, was the massacre of Reproire IV. When the population of hive primus aligned themselves to a rogue cardinal and revoked their adherence to the cult of the imperium, the warbastards were sent in. in there eagerness to join the fight, they forgot to check the spelling of their target on the brief, and instead committed wholeheartedly to purging the neighboring Primea hive. The mistake was only discovered by a scribe some 10 years later, at which point the entire planet and the population of 2 moons of Reproire V had also turned renegade. Widely regarded as a bunch of imbecilic morons by the older marine chapters, the Warbastards were given a 100 year penitent crusade as penance for their errors.
Sense make not does So they Butchered some Hive with out any provocation and allowed People to go renegade and renegade how? Xeno, Chaos what or decided to not go to church on sunday? **so now your guys are Heritics and Possibly working for the Word Bearers the =I= has been informed Please ready your headspace for a Bolter round.** and from doing so all you got was a Penance Crusade for a Hundred years the Lads From the Badab wars got that and well they did something much worse your chapter would have been meeting the Purge hammer.
The chapter is organized in the same 10 company structure as a codex chapter, however they are unique in that they have 2 full 10 man squads of terminators in each of their 4 companies, and have no ‘first company’ as such. The company commanders enjoy a large degree of autonomy because of this, and do not have to rely on other parts of the chapter quite so often.
The standard organization is:
Commander and command squad
2x terminator squad
3x tactical squad
4x assault squad
Bike squad
4 companies or 10 companies? And 20 Termies Per 4 chapters No first Co?...Why. Oh and Codex chapter then alot of we changes how we do stuff = not a codex chapter oh and the snowflakeness makes no real sense as to why there are 20 termies per 4(or so) compaines.
The warbastards have largely kept the belief system of the redemptionist crusade, and are as such violently opposed to any kind of mutation or psykers in any form, and even go so far as to attack librarians from other chapters. Needless to say they have no librarians, and an above-average number of chaplains.
So they are the Male SOB's but more heretical than Female Marines. and If you attacked ANY chapter Psykers that chapter is going to open 47 cans of Emperor Brand whoop ass on your guys.
however more often they are single syllable words that can easily be taught by the chaplains, as reading has never been the strongpoint of redemptionists. Often, therefore, they go to battle with simple cries of ‘die’ ‘kill’ or ‘burn’ – multisyllabic words often escaping their vocabulary in the heat of battle.
So male SOB that are like the Word Bearers and the World Eaters....
It is thus that the warbastards charge forth into the universe, on a mighty crusade of penance for a reading error that a 3rd grader would have noticed, flamer in one hand and chainsaw in the other.
Okay so I was somewhat Nice about things Now Take your fluff to LA and Have them do their thing.
Oh And as for the First post those Tau Tanks look familiar.