"I'm concern about changing anything to the sysdba user, as long time ago, changing a permission to this user on the database, makes the whole application to stop..."
That was probably a case of you (or someone) assigning a server role (sysadmin or dbowner) to the SYSDBA user in SQL Server. When you do that, SQL Server assigns the "dbo" (i.e., default owner) schema to the SYSDBA user account, at which point any application that logs in with the SYSDBA account has to prefix all table references with the original schema name of each table owner (in SLX's case, this is also "SYSDBA"). Since SalesLogix isn't written so as to include those prefixes in its SQL queries, you get "object not found" errors pretty much immediately - if objects like tables aren't part of the user's default schema, they're treated as if they don't exist, unless references to them are qualified with a schema prefix.
You might think this is a deficiency on SLX's part, but if all table references in queries were qualified, then SLX could be run under practically any SQL Server user account, and it would actually be much less secure as a result. Anyway, it's a fairly simple explanation when you think about it, but you rarely see it explained among SalesLogix folks...
Anyway, explicitly granting a specific access permission (such as "View Any Definition") isn't the same as assigning a server role. Permissions like that don't affect the schema assignment, so it doesn't (or shouldn't) affect the interpretation of SQL queries (and thereby the operation of the program).
