by Xyz » Mon Jan 26, 2015 6:17 pm
You could not use the 1.12 client without the linked flight paths, period.
If you wanted a 100% accurate vanilla experience, I hate to say it, but you either played it or you missed it. While older patch versions of mangos do exist, all the way back to beta 0.6, they rely on the same source and thus not only will there need to be years of development on each patch to reverse engineer it unless you got a large team working 8 hours a day on it, and even then, it would still take longer than blizzard because they have to reverse engineer it which takes longer than just writing it.
The reason item changes are feasible I've already explained elsewhere, but its because the client doesn't have anything hard coded for items, and gets all item data from the server. So a database change on items is a fairly minor tweak. If you have an interest in finding out what is possible and what is not, check out a project like getmangos/cmangos and set up a core and tinker around. You'll find a lot of limitations based on the client though there is also a lot of freedom as well, just not the kind that is suitable for what you want.