I wouldn't say ERZ3 is death pit hell apart from that one room with the reverse-gravity platforming over square platforms. As it so happens, that's also by far the worst room in the level. Apart from that, the only room where pits are much more than scenery is the first room after the initial hallway, but I don't think that one's inappropriately difficult. If that one room is replaced with something more adequate (and interesting!), it think it will be fine.