As for fighting style I think @Uriel1339 hit the nail on the head there. As for titles perhaps Pack Master? As to the rituals I like the idea of them testing their worth with the panthels. Also as a sign of respect and desire to be Like a panthel in battle the recruits perhaps paint themselves the color of the panthels themselves.
Hmmmmm for Recruiting Rituals what about a group run across an area of land cultivated to incorporate lots of the different plants, survivors then finding themselves in a cove inhabited by sea beasts. They must slay the brood spawn and drive off the matron. Those few who survive then face the test of the Panthels, essentially mimicking the trials our squad faced after making land fall.
I think Pride Master would be more fitting seeing as we're not a Chapter with hounds but panthers aye? Perhaps those would be Sergeants in the future and our brothers all just become Pride members, stick to that Claw-Brother Fang-Brother for Assault and Tacticals respectively aye?
Dreadnoughts aren't really a thing with the White Scars and their descendants though. We've talked about it since Terra but nothing has really come of making it a thing. I do like the idea of gold dreadnoughts that the future Chapter warriors look at as like divine warriors chosen by the Emperor himself to rise beyond the grave and carry on the fight though.
Possibly for some of the oldest, Or possibly If we one day find a experimental blue prints for something like a dreadnought but faster, Also our chapter seems like Raven guards and The white scars with a few tactics combined.
Raven Guard + White Scars with pretty damn strong faith later on once the Chapter is pure Savage Landers. Which all works perfectly due to our heritage, our Counter-Intelligence Trait and that we have a shrine world out there that loves us and our Death World is made up of fairly superstitious folks.