Most of the complex rules were added at some stage in the historical development of Chess, and stuck because they turned out to be significant improvements. So abandoning these rules can be expected to be a step back, both in time and in quality.
Simplified Chess

Most of the complex rules were added at some stage in the historical development of Chess, and stuck because they turned out to be significant improvements. So abandoning these rules can be expected to be a step back, both in time and in quality.
I would suggest that if we don't examine both why the rules were added (double space move for pawns on first move, as an example) and how new rule space (like this variant) affect play, then we are doomed to an unimproving version of the game.
As you pointed out, changes made it better. Examine the changes in this variant if only for the mental excercise of questioning why they simplify the game and what the original rules were put in place for. Know your Chess history! :-)
The Pawn double-push was added no make the opening less boring. This was an almost universally felt defect of the original Shatranj, but different branches of eveolution of the game solved it in different ways. The Asia variants (Xiangqi, Shogi, Makruk) all moved up the Pawns in the initial position. In Chess the double move was invented. Likely it started simply as moving before your turn, if the opponent allowed it. (and then did the same). If his plan was to capture your Pawn after the first step, however, he objected, and you had to take back the formally illegal second step, after which he would capture you. This is how e.p. capture started.
Many variants have a way to speed up bringing the King to safety without trapping a Rook. In Chaturanga, which even pre-dates Shatranj, Kings could make an initial Knight jump, after which the Rook could pass behind it. Cambodian Chess still has this. In Grant Acedrex the King could initially jump two squares orthogonally or diagonally. Western Chess sped this up even more by combining the Rook and King moves into castling.
What if you removed the complicated rules from chess, would it still be interesting?
http://www.chessvariants.com/invention/simplified-chess
Simplified chess removes 7 rules from standard FIDE Chess to create a new game that is deceptively simple, yet has a whole world of new strategy and tactics waiting to be explored.