1. You need to check the smart money data for conclusion. Increased OI might be due to closure of existing positions by smart money and fresh positions by retail investors.
2. All filters are unique..In volatile market give high weightage to F&O data
3. The weightage can be assigned but there is no standard rule
4. I rely on this method..It also depends on the results you are getting..If your accuracy is high then you may continue with this system.