That deck actually saw play in one game and managed to win, thanks to some very good luck and the aforementioned very good synergy
Similar cards in the past like Jaspera Sentinel have forced you to tap a creature to get your mana, but tapping any permanent to do it makes this a lot more flexible
Commander is a much slower format by comparison, so Mental Misstep is far less powerful there
I'll have plenty more to write about that set, as I went on to become its lead designer
Nowadays, there are multiple other answers just as efficient as Fatal Push like Prismatic Ending and Unholy Heat, and the card has been slowly replaced with these alternatives as they are just more versatile
2.) Jeweled Lotus only creates a toxic environment for cEDH, but creates more of an enjoyable environment for casual EDH