Hi Daniel,

It pains me quite a bit to say that replicating between different versions
of SQL Server (using transactional\snapshot replication at least) does
require a fair amount of forethought and intervention from the end-user (the
larger the version difference, the greater the effort required) today even
though our documentation states that your configuration (2005->7) is
supported (well, it is certainly possible... within limits).  One of the
main reasons why customers like yourself have to go through such painful
experience is that we need to strike a very delicate balance between the
conflicting needs of supporting new features in newer versions of SQL Server
and maintaining backward compatibility with downlevel subscribers.
Unfortunately, compromises need to be made one way or the other thus making
virtually all customers unhappy about something. Now, to answer some of your
inquiries in your post:

1) & 2) are basically the result of a conscious decision of not supporting
SQL Server 7.0 from the SQL2005 management tools but I would encourage  to
file a design change request (DCR) at the MSDN product feedback center just
so this gets a chance to be reconsidered in a future service pack. In the
mean time, configuring a subscription to your 7.0 subscriber using T-SQL
commands would be the most convenient option.

3) By default, SQL2005 Management Studio includes copying column-level
collations for table articles as part of the article schema options. As
column-level collation is not supported by SQL Server 7.0, you would need to
exclude the option by changing the article properties through the UI or use
sp_changearticle to exclude 0x1000 from your article schema options. As a
precautionary measure, I would also like to mention that user-defined data
types are schema-qualified in SQL2005 but not in any previous versions, and
while there are undocumented options to tell the snapshot agent to script
the user-defined data types without schema qualification, I would recommend
that you simply enable the 0x20 schema option to convert all user-defined
data types to the corresponding base types if you try to replicate from
SQL2005 to any lower version subscribers.

4) By default, primary keys are replicated as unique indexes if you
configure replication using the SQL2000 Enterprise Manager. To ensure that
primary keys are replicated as primary keys to your SQL2005 subscriber, you
can either check the "Include declarative referential integrity " box on the
article property sheet or simply enable the 0x2000
(PrimaryKeyUniqueKeyAsConstraints) schema option using sp_changearticle. If
you plan to reinitialize your SQL2000->SQL2005 subscription in the future, I
would encourage you to spend some time understanding the implications of
doing so and make the appropriate adjustments to your replication
configuration.

Sorry for the rather long-winded post, I certainly hope that the information
I have given above proves useful to you.

-Raymond