no!
I regularly check for overlaps with other map mods and will mark them here if necessary.

in some cases allocating more RAM helped.
there is a tutorial.

the Fort is completely closed.
you can either clear the path with a sledgehammer or build your way over the fence with stairs.

I can only recommend a new game save.
I cannot and will not give any support for this!
if you want to do that you have to get the information from somewhere else.

yes the mod is both SP and MP compatible