you cannot remove the minimap altogether but you can disable any kind of use by creating a text file and import it into your map and name it war3mapMap.tga
this will make the minimap blank and nomatter what unusable for seeing units etc, its also a very good way to introduce 3d maps. set the camera high enough just to see the whole map, screenshot it and turn it into a tga or blp and you have a nice looking 3d map.
try war3mapMap.blp as the custom path, not the actual name of the file. you must checkmark custom path on the object manager for imported file and type in the path.
yes, blp will fix the problem. previews use tga i beleive and blp for maps. your path is correct so just change the .tga to .blp and it should work. Tested it myself incase and it worked.
Finally finding about some of the bots that are flooding the users online - bytespider apparently is a huge offender here - ignores robots.txt and comes in from a ton of different IPs
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.