Use Of BUILTINAdministrators Account

This message is in reference to a previously posted SLQ Server 7 question and answer regarding the BUILTINAdministrators account (dated 11/19/2001)

Original Question: I'm using Mix-Mode Authentication. Can I remove the Builtin/Administrator loggin ID
without cause any harm to my current Login ID user(Windows NT user)? Are will
removing Builtin/Administrator what harm will this cause to my server?

Answer to above: The first thing I do after installing SQL is remove the Builtin/Administrators account for
the SQL Server. Depending on how you set SQL up, this should not affect any NT
users, unless you granted them access to the server through the local Administrators
group. This is not the prefered way of granting access, however. This will give any
administrator on the machine access to all of the data, which you may not want,
depending on the confidentiality of the data.

Situation: (SQL Server using Mixed Mode Authentication).
If the Builtin/Administrators is disabled or deleted, and the server rebooted, SQL Server will be initiated but, the SQL Server Agent won't be.
Signing onto SQL Server as SA will not be able to restart SQL Agent nor will an NT user with administrator capability have any better luck

Question: What specifically in NT and SQL Server does one need to change to get around this situation.
The SQL Server documentation is not very helpful regarding the use of this login.

While attending a SQL 2000 Administrator course, two of my colleagues were told to always delete this account but were not given any reason or explained the consequence of this action.