What we are plotting on the map is the universe in 'comoving coordinates', which are determined by cosmological parameters (amount of luminous matter, dark matter and dark energy in the universe). They're the ones that determine the global curvature of space, and in the past few years have been measured very accurately (eg., with WMAP).

What you seem to be objecting to (among other things) is that the map should somehow depict local curvature as well (eg., you talk about closed timelike loops, black holes, etc). However, note that in that case you'd also have to object to every map of the _Earth_ that has ever been made, because it doesn't take into account the small increase in Earth's area due to mountains and depressions ("And their map would be f**ked around mountains for obvious reasons").