We have some info in our Wiki: http://wiki.plarium.com/index.php?title=Elixirs:SWOE

they are nearly all wrong!

btw here is more accurate info:

http://prntscr.com/bbtyhk

pls note numbers in red are estimates, others were double-checked by me and are accurate.

here is official info on cavalry defense elixirs(second number inside brackets):

http://plarium.com/forum/en/sparta-war-of-empires/game-tutorials/topics/mounted-peltast-stats-/

sidequestion, which are the best high level exilers to use. Is it for example stil worth it to use high level light infantry since that always gonna be used loads or is it better to make the stronger units stronger.

it is million dollar question

many players don't use max lvl elixir or only 1-2 and have optional 1-2 of lvl 4 or lvl 8 as they are cheaper to swap around. Don't know many players who set 3 top lvl elixirs and never swap

I have 2 set and swapping one.

I can admit that I set 3 and forget them.  I have had level 10 Offensive Phalanx, L10 Defensive Phalanx and Cavalry for at least 6 months.  I don't bother with anything else for very specific reasons.