I tried be dex eldritch warrior and it seems very veak, my melee attack even with +3 bonus and +1 bonus of rapier +1 do very low damage and crits and all my spells at lvl 3 is first leveled like burning hands or magic bolt. Will my character be stronger on 4 and 5 levels? Right now im with 20 AC and low offencive skills feeling like pretty mid tank
I linked this already in the other thread you made about the Eldritch Knight, read it:
https://rpgbot.net/dnd5/characters/classes/fighter/subclasses/eldritch-knight/In it is also a link with a comparison of raw weapon damage vs. weapon damage with cantrips,
https://rpgbot.net/dnd5/characters/melee_cantrips/. The Eldritch Knight seemingly gets stronger in higher levels, especially from lvl 7 onwards. I find that much more promising than playing as Ranger or Monk, thinking, wow, it's great (at low levels), and then later on suffering from a stalemate. In my opinion you don't need to make a Dex based Fighter just because you are playing as high elf.
In release there also will be difficulty settings (I presume). If the current difficulty will be Normal (as most fights are quite easy but not that boring, and some are a bit more demanding), in the worst case you could lower the difficulty to play the class and race with the equipment you like.
Edit: i made me a high elf Fighter to try, with 15 Str, 10 Dex, 15 Con, 14 Int, 10 Wis, 10 Cha, origin is with Acrobat, cantrip would be Shocking Grasp. I don't like the low Wis because that's the saving throw against very unpleasant stuff, but as elf you have the big advantage of proficiency against charm spells and immunity to sleep. I would not like such a char as Barbarian or as Fighter if I would go Battlemaster, but for Eldritch Kinght it seems totally ok, as you can take two points at lvl 4 and don't need a feat.
On the other hand, with the appropiate weapon a Dex build will not have lower damage (longsword and rapier are both 1d8), if you are not satisfied with your damage with 17 Dex and a finesse weapon, you will also not with 16 Str and a strength weapon. As Eldritch Knight you need magic to your weapons. Advantage of the Dex fighter is the better ranged weapon damage.
