Yes, Remkar, that was what I tried to say. Your explanation is probably clearer than mine.
I want to give the example with numbers. Lets take a recent game that BackGa won against TAVLII:
BackGa:
ELO-Change 280 -> 289 (+9)
EAS-Change 1595 -> 1611 (+16)
TAVLII:
ELO-Change 220 -> 212 (-8)
EAS-Change 1526 -> 1510 (-16)
If the same game had been played with TAVLII in Platin league (and an EAS of 1526) and BackGa in Gold league (and an EAS of 1595) then after the game TAVLII would end with an EAS of 1510 (-16), perhaps losing some shields in his Platin Level and BackGa would end with an EAS of 1611 (+16), perhaps winning some shields in his Gold Level.
Thus, the EAS calculation (No.3 in Remkars explanation) is independent of Arena levels (No. 2 in Remkars explanation) and also independent of the players ELO (No. 1 in Remkars list). If you want to calculate the EAS change, you only have to know the EAS of both players and the game result. Nothing else is plugged into the EAS formula.
The formula to calculate EAS is more or less the same as the formula to calculate ELO - with some differences. The most important are:
*) With ELO, every player starts at 0. With EAS, every player starts at the beginning of each Arena season with 1500.
*) For ELO, every ranked game counts (Arena + Non-Arena games). For EAS, only all Arena games of a single season count.