While I do not have this tank I have watched a lot of reviews/builds on it and just re watched one as I do not know which side screw you are referring to. I do know some BRA's do have a screw in the side that holds the shroud cover in place, I thought yours simply screwed down over the deck as seen in this video:
In any event I would suggest the following:
Watch some video's that show how your RBA / tank is built.
Ensure everything is properly put together/secure.
If it is running too hot try lowering the power (volts/watts/temperature.
If after the above it is still too hot, you could try building a higher resistance coil, higher Gage wire or more wraps etc, here is a handy reference tool:
Coil wrapping | Steam Engine | free vaping calculators
If this is your first experience with a sub ohm tank they do tend to run a lot hotter than the smaller ego type ones that use higher resistance coils. I found this out myself trying to transition from an ego/aspire K1 tank to a crown sub tank.
Lastly if you do not find a solution from this or other replies/videos, if you have a local vape shop that has good people take it in and ask them to look at it.
Good luck and happy vaping!