Is there a DDL generator out there where you can start with CSV/TSV to create DDL for Cassandra

Cassandra 1.0 uses a minimum of 1MB of heap per CF. So, 1000 or 2000 CFs will be okay for typical heap sizes, but 10000 will probably not be. JVM GC does poorly with very large heaps; I recommend staying under 8GB.

No there's no way of configuring SQL Server to do what you want to do.

Under snapshot isolation the call to sp_tables gets blocked waiting for a shared key lock on one of the system base tables (sysschobjs) when doing a SELECT from sys.all_objects

The Using Row Versioning-based Isolation Levels topic in BOL does say:

SQL Server does not keep multiple versions of system metadata. Data definition language (DDL) statements on tables and other database objects (indexes, views, data types, stored procedures, and common language runtime functions) change metadata.

Even under TRANSACTION ISOLATION LEVEL READ UNCOMMITTED the call to sp_tables ends up blocking however, whilst the straight forward SELECT ... FROM sys.all_objects is no longer blocked the same query references the HAS_PERMS_BY_NAME function in the WHERE clause. This appears to start a system transaction (CMetadataAccessor::CMetadataAcce) at a higher isolation level and ends up getting blocked waiting for a shared key lock on sysschobjs again.