Can I determine if a stored procedure uses dynamic sql without parsing the definition? Since there seems to be no way to strip the procedure definition from comments  without parsing cf. this, there seem to be no reliably T-SQL query to answer this question.  

Or can I get this information from any system view?

cf. my question about stripping comments
No. There is no flag or metadata about "UsesDynamicSQL"

You have to search the definition...

There are 2 ways to execute dynamic SQL


sp_executesql
EXEC (.. or EXECUTE ('


You can search for the first in sys.sql_modules, the 2nd using LIKE

WHERE
   REPLACE(definition, ' ', '') LIKE '%EXEC(%'
   OR
   REPLACE(definition, ' ', '') LIKE '%EXECUTE(%'
   OR
   definition LIKE '%sp[_]executesql%'