As for arrays, I think of it as a huge variable who can store many variables. You should be able to choose the size of array, the type of data it can store(for example strings or numbers).
As for editable syntax, I think it could look something like this: "set array x(array name) (x)(index of certain variable in that array) as x(what kind of new variable you want to put in that certain array)". So this setup would look something like this: "Set ArrayX (3) as (hp(entity attribute) of selected unit)".
Also I think it could be used for player array, entity array and global array.