yes

Unfortunately no, as boosts from skill toms are multiplicative, not additive. In the case of the former, at level 7 cardiel will heal all allies by 9% (7.5%+.375%+.375%+.75%). With the latter, lilitu will place a shield equal to 13% of her max hp (10%+1%+1%+1%).

If this is true.. they why is the description for Lilitu's shield for example.. +10% and not +1%? The visible size of the shield bar on chracters certainly appears to grow by 10% each time, not 1%.

Because it is 10 percent - of the original amount. 10 percent of 10 percent is 1 percent (also, technically Carpe's numbers are slightly off; the first increase is 1 percent, the second is 1.1 percent, the third is 1.21 percent, each time 10 percent more). 

Heals and shields work like damage does. The percentage increase mentioned is a percentage of the damage/heal/shield at that time (including any prior increases), it's not a percentage of the character's Max HP. 

Thank  you  so  much  for  the  info.  i  tried  to  find  that  for  hours!!

- Damage

- Healing

- Shields

Their value is multiplicative

- Debuff Chance

Their value is additive 

That is new but also seems not true to be honest. Not saying it isnt (wont be surprised by anything in this game). But having to spend 6 epic books to go from a 7.5% to a 9% seems quite uhm worthless? Going to look into this. Curious where you got your information from.

I  agree  that  it  is  extremely  costly  epsecially  with  legendary  tomes  to  get  such  a  small  increase.    Really  only  good  for  cooldowns  and  buff  chances....

You realize that it heals all allies and it's on his A1, yes? You really thought he was going to heal all allies by more than a quarter of their health every time he hits an A1? Cardiel is extremely strong as it is, but there are limits... 

As for where people get their information from - from playing the game. :)