"End of your current turn."Actually the samurai ability is bonus action activation lasts until the end of your *next* turn. So bonus action at beginning of turn, attack, next turn attack, then it ends. The ability can give you two turns of advantage.
This is an example of powergaming I like. Samurai were often excellent archers, but these days everyone thinks samurai = katana
Those are really narrow and restrictive ideas of the Paladin, Rogue and Fighter classes you appear to be using.To understand where I come from is to understand that if someone plays a pally at my table, I expect him to act it out. And no holy knight of lawful goodness would see any point in taking up the job of a guy who steals from other people. Nor would he take up the life of a common soldier, whoring, drinking and gambling to spend their war loot.
Of those builds I only would allow 1. at my table eventually 2. cannot analyse at the moment, the third is for my personal taste an absolute munchkin build.
If a pala at my table decides to take rogue as a second class he is in for a check whether he has fallen and lost all his pally powers. Same goes to change to a fighter fighter.
A pally strives to be pure and devoted, it is imho pure minmax powergaming to multiclass a paladin for any other than highly plot/rp justified reasons.
. . . But would you have allowed the swashbuckler if they didn't steal from people? And would you have allowed the half-elf to play a fighter if their concept was a noble knight rather than a common soldier, looting, brawling and suchlike?[MENTION=6802951]Cap'n Kobold[/MENTION] I prefer all PC Pala being of the classic LG type, normally, and i do restrict classes and races and Equipment and such, but the Players know upfront. If one of my Players would ask me for some other class i would ask to give a backstory to why it went that way and how it fits into the campaign. Normally i do not like multiclass, and i do see no reason why dwarfs should be wizards. Drow are Mobs.
My Players have got their own preferences, within their Group they normally agree on no more than 50% of the group not human.
I would not mind more than that but depending on the campaign Setting : for Planescape definitely yes , for Ravenloft definitely no.
In my current greyhawk campaign i do only allow human, halfelf, Gnome, halforc, tiefling (devilbased), and it works out for them.
Pary is human swashbuckler (SCAG), halfvelven fighter, human Paladin and Gnome Illusionist.
One combo I think deserves special mention- The Hexblade Bladelock heavy weapon fighter. You talked about weapon attacks with Warlocks in the darkness, but this should be treated separately I think since it allows the use of heavy weapons and thus GWM with Cha, and thus enables Elven Accuracy, otherwise you are stuck using Dex weapons.
1) Able to use heavy weapons with Hex Warrior as Cha based, thus opening up Elven Accuracy for GWM, Polearm Master attacks, and Sentinel attacks plus increased threat range, or just GWM for Greatsword/Maul attacks.
2) Able to get consistent Advantage thanks to Darkness, Shadow of Moil, and the Specter minion.
Don't forget the expanded CRIT range with Hexblade's Curse, allowing for potential Bonus Action attacks with your Greataxe.