Morrowind used Gamebryo though, albeit a very early almost prototype version

Been playing. Been trying mods. Used BOSS to help with the load order. Question. I notice some of the mods listed on BOSS as having dirty edits ie ITM or UDR. While i know certain mods im using have deleted Navmesh errors (one or two the authors have noted dont need to be fixed), is it advisable to use tes5edit to try and clear the ITM/UDR errors??. Will they cause problems later? Or can they be ignored and just lazy cleanup by modders?.

They other question is - some recently released mods like Welcome to Salem (looks like it got removed from nexus), Peaceful Valley & The Last Altar looked good but for whatever reason causes CTD when im creating a new charachter (took me a long time to narrow down the what was causing the ctd's...out of 120+mods installed..). anyone had those working without a problem?.