Hey, welcome to OpenStreetMap and thanks for contributing! I moved that one crosswalk back in place for you, no harm done. :) https://www.openstreetmap.org/changeset/151969273

If you decide to do any drawing or moving of stuff like buildings or roads in the future, please check out the wiki page below. We use a specific offset in Montréal, and it's important that everyone use the same number or stuff ends up misaligned. For adding points of interest like you've been doing, it's not super important. https://wiki.openstreetmap.org/wiki/Montr%C3%A9al

If you have any questions, feel free to message me!