More dex will get you more damage.
The damage modifiers are all additive and all apply to your base weapon damage. So +30% from a 20 might, +25% from weapon spec and focus, +15% two handed style, +30% exceptional weapon, and savage attack modal +20% will get you +120% damage
If your weapon has a base damage of 20 you'll do 20x(1+1.2) = 44 points of damage per swing. An 18 dex will swing this 24% faster than a 10 dex. Even in full plate an 18 dex will swing 24% faster than a 10 dex.
With a 3 intellect durations are pretty short so avoid them where possible. Disciplined barrage does increase accuracy which gets you more hits and more damage. A knockdown makes them prone which gets you more hits and stops any incoming damage but takes more micro as the disciplined barrage is a one click and done ability which means you'll use it every combat while a lot of times you might forget to use knockdowns.
Estocs are really good, numbers wise the -5 DR is hard to pass up. The weapon group also has flails for using with a shield or single hand for accuracy and a warbow for ranged damage.
Great swords will hit for less damage but there are some nice magical ones throughout the game. They are bundled with pikes which also have some nice magical ones in game plus they have reach which is advantageous in many applications. Warhammers are a solid one hander, and the ranged arbalest and arquebus are two of the best big damage initial shot weapons in the game. Start with a ranged volley then switch to your sword.
The difference in damage between estoc and greatsword, while present, is not so great as to make either a bad choice. Estoc's bigger damage compared to opening volley of arquebus/arbalest followed by great sword or pike which also lets you stand behind the frontline.
My main is a dwarf two hander spec'd for damage and I really like the class. On hard at level 10 now went with the estoc/warbow. Wearing exceptional leather enchanted for pierce proof and +2 dex along with the blunting belt. He hits hard and fast with enough endurance, DR and deflection to stand in the front and beat people down. Leads party damage by like 2.5x the next closest companion.
The being able to stand in the middle of the battle is what sets a damage spec'd fighter apart from a melee rogue or a barbarian, which are both fairly fragile and require more micro and attention from a healer. In my opinion it is easier to spec a fighter to put out DPS than to make a durable rogue or tanky barbarian.