Bulk Delete On Operational Data

Hello,

I read several articles of newsgroup about the bulk delete, and I found
one way is to:
-create a temporary table with all constraints of original table
-insert rows to be retained into that temp table
-drop constraints on original table
-drop the original table
-rename the temporary table

My purge is a daily job, and my question is how this work on a heavy
load operational database? I mean thousand of records are written into
my tables (the same table that I want to purge some rows from) every
second. While I am doing the copy to temp table and drop the table what
happens to those operational data?

I also realized another way of doing the bulk delete is using BCP:

1) BCP out rows to be deleted to an archive file
2) BCP out rows to be retained
3) Drop indexes and truncate table
4) BCP in rows to be retained
5) Create indexes

Again the same question: When I'm doing the BCP is there any insertion
blocking to my original table? What happens to my rows meantime to be
inserted?
Does BCP acquire an exclusive lock on the table which prevents any
other insertion?
Does any one have an experience with a BCP command for querying out 2
million records, and how long will it take?

I appreciate your help.