In my experience, it took me a while to take off the stock airbox and the clamps on the intake pipes. The hose clamp on the stock piping for the OCC was hard to get off too. Nothing major with the rest of the installations. The BMS DCI rubbed against the engine and damaged the filter, so i switched to a smaller filter. So far i havent have any problems with the filter at all and they sound the same.
The OCC hoses are now tucked in nicely. I have no issues with the engine cover. If you want to check the catch can you will need to take off the hvac filter and cowl to get to it, just make sure you dont overtighten the catch can.