Installed it eventually and will have a look what the siege\battle issue might be.
Edit: corrected a number of things before even testing the battle issue
corrected mismatched historic_event texts (causes crash)
corrected invalid EDCT references
moved declaration of counters before first use (script)
removed invalid script references to buildings
provided full set of sound text files for proper sound generating
provided missing 'xyz_name' entries in export_buildings
provided missing unit sprites
corrected invalid code in script
provided missing character name entries
removed surplus files (lookup, enums, model files)
provided automated installer
I did a siege battle england\rebels and had no problems (providing the missing files might have done the deed), other then the 'flash' button not working. Not sure where that is linked.