Sure... just remove the columns, reinstall the mod and you are done. Simply because you tried to install the app more than once... so the columns already exists. Remove them: alter table ibf_groups drop column g_upload_use;
alter table ibf_groups drop column g_upload_maxsize;
About the folder, you have to create a folder called images in your uploads folder on your FTP.
Unless you are using a different version of the mod, which I doubt, should work... the detection is automatic. When the folder is there, you'll see no message.