Wow, thanks for all the answers! Great to know these kind of issues have mostly been taken care of.
For the flightpaths it's really just the minor difference of "passing by" instead of landing and starting shortly after.
Terrub and Peacebringer explained this perfectly.
- Something more important: Line of Sight system is broken on most MaNGOS servers. Objects like trees break line of sight, which they didnt on vanilla retail. This is a major disadvantage for rangers/casters.
Would be awesome if this works/ will be working on Nostalrius!