i think the best what can be done here is split achieves on 2 tabs

- account achieves = all achieves from all characters

- character personal achieves


in that way we can keep happy both hardcore achieve hunters and just people who for example hate to redo all TG/DB

stuff on mag toon who has nothing to do with sithis followers or redo vamp/ww skil lines just for achievement and de-spec

them immediately after that.


separate tabs also brings an opportunity to link let's say recent toon undone HM but completed by you on different one.

This again???

The achievements are supposed to be character-specific.
Otherwise, how could we check which character has missed what skyshard or exploration location, who has yet to learn which crafting style or do what PD group challegne for the skill point, and so on.
It also would make no sense at all to have fresh characters straight out of the tutorial flaunt titles your main earned. Especially not when some classes have easier times at some content then others.

And the titles aside, the only thing achievements -actually- count for is dye unlocks and the occasional collectible - which -already- are account wide.

As with all else, if you want something badly enough, you will have to spend the effort again to get it for an alt too.
And if you don't want to spend the effort, you will have to do without on this or that alt of yours.

...


That being said...
...we -could- use a "account overview" page. Accessible from the character selection screen, and giving us a complete achievement overview for all our characters - who has done which one when, etc. Might as well shift the dye unlocks and collectibles there too.
And then... possibly add some new rewards for multiple achievement completions, like... doing mainstory with every class, or reaching some alliance rank benchmarks in every alliance, or reaching level 50 with every race, or stuff like that... heck, they could even give out some "rare drop collectibe" (like halloween masks or IC skin/polymorphs) or "limited time crown store" (like old costumes) rewards as unlock for highend achievement multiple completions... like, either get lucky with lockboxes, or work hard to get this or that...