Referring system views and functions in production functions
There should be no real performance problems related to using the system objects to build your T-SQL. 

Consider also that building your dynamic T-SQL is probably a much lighter load on your server than actually running the T-SQL statements that you generate.

There are also INFORMATION_SCHEMA views, but these only partially cover the system objects.  I mention this only to warn you that, although once recommended, it has many limitations and I do not use them any more.

Likely the biggest issue for your code is that system objects do change over time.  Probably most changes would not affect your code generation, but you should plan in advance before upgrading to a new version of SQL Server.  

SQL Server documentation usually details out the changes for the next upgrade.

For example, here is a link for SQL Server 2014's breaking changes.
https://msdn.microsoft.com/en-us/library/ms143179.aspx#SQL14