Get DB Table Size

The following will list the size of each table:

SELECT 
    s.Name AS SchemaName,
    t.NAME AS TableName,
    p.rows AS RowCounts,
    SUM(a.total_pages) * 8 AS TotalSpaceKB, 
    SUM(a.used_pages) * 8 AS UsedSpaceKB, 
    (SUM(a.total_pages) - SUM(a.used_pages)) * 8 AS UnusedSpaceKB
FROM 
    sys.tables t
INNER JOIN 
    sys.schemas s ON s.schema_id = t.schema_id
INNER JOIN      
    sys.indexes i ON t.OBJECT_ID = i.object_id
INNER JOIN 
    sys.partitions p ON i.object_id = p.OBJECT_ID AND i.index_id = p.index_id
INNER JOIN 
    sys.allocation_units a ON p.partition_id = a.container_id
WHERE 
    t.NAME NOT LIKE 'dt%'    -- filter out system tables for diagramming
    AND t.is_ms_shipped = 0
    AND i.OBJECT_ID > 255 
GROUP BY 
    t.Name, s.Name, p.Rows
ORDER BY 
    s.Name, t.Name

The above is discussed here.

Get Referenced DB Entities

The following will show what DB entities are referenced:

USE DB_NAME;

SELECT referencing_schema_name, referencing_entity_name, referencing_id, referencing_class_desc, is_caller_dependent
FROM sys.dm_sql_referencing_entities ('NAMESPACE.FIELD_NAME', 'OBJECT');

The above is discussed here

Get Row Counts from Tables

select t.name TableName, i.rows Records from sysobjects t, sysindexes i where t.xtype = ‘U’ and i.id = t.id and i.indid in (0,1) order by TableName;

The above is discussed here and here.