What are the basics of Gladiator/Paladin?

[Enkidoh]

End-game Flash might suffer in usefulness, but early on (especially in the early dungeons), it's power cannot be underestimated. At level 15-20 you don't even have access to Rage of Halone, and have to rely on Fast Blade + Savage Blade/Riot Blade only.

In places like Tam Tara and Copperbell you'll be having to deal with lots of adds/links at once, and it is the only way to get all those extra mobs back onto you off your healer. I've been doing the early dungeon runs a lot lately (for a friend, to get her the Acolyte's Boots, so far without success ), and I normally open the fight with Shield Lob, Flash, then just repeat Fast Blade +Riot Blade (to recover MP), and repeat, until there's one mob left and I swap Riot Blade for Savage Blade.

Yes Savage Blade gives more individual hate than Flash, but given Savage Blade only affects one target where as Flash is AoE, it's not going to do much to hold the whole shebang onto you. Or at least, that's how things have seemed for me so far (as I haven't gotten to end game I have no idea how different tanking is there so I'll take your word for it on that.)