Try to use HeidiSQL - http://www.heidisql.com/ Or better if you have ssh access to your host you can use following to upload; mysql -u username -p database_name < file_name_to_be_upploaded.sql to backup; mysqldump --opt -Q -u username -p database_name> file_name_to_be_backup.sql
or you can split this SQL file to small one ( i assume that you have size issues ) i see one tool for that somewhere try here http://www.madbabble.com/sql-dump-file-splitter
No, just increase the maximum file size in your php.ini. You may also need to increase the max execution time.
Also, if your host allows remote connections use the backup utility in the MySQL Administrator program from the MySQL website.