To undertake seizure under Section 67, the officers should be having authorisation from Joint Commissioner (JC) and the JC can authorise the search and seizure only when he has reasons to believe that the goods are liable for confiscation. Many times, the department would not be communicating such reasons to the taxpayers.
With respect to cross-jurisdiction, the state tax department can initiate the proceedings if the same is an intelligence-based enforcement action. This was clarified by way of a circular by GST Council.
However, we can understand the reasons behind the investigation based on the questions asked by the department during the summons. Once we understand the reasons, we can check whether the department is conducting the investigation on same proceedings which are already covered by the audit done by central tax authorities (specific Audit Para). If it is covered, we can take shelter of Sec 6(2) of CGST Act, 2017.Ideally, the department cannot invoke Section 74 for issuance of SCN when audit is already conducted by the department. There are many settled jurisprudence under Pre-GST laws
With respect to time limit till which the department can ask for information, they can ask for the same up to 5 years from the due date of annual return for respective financial years.