You can delete the data by committing small chunk of the data which will help tlog file to grow minimal with very minimal open transactions.

Usually after large insert/delete operation SQL Server update statistics. However if it won't do it, you can do it manually to ensure good performance of the query. You can also plan for reindexing.

You can also export table data before deleting records and keep the backup for future reference; in case anyone might required.

HTH