The single most important answer to your question is tuning.
A good ECU, set up with proper error margins and limits, and tuned with accurate equipment by a competent tuner will make more difference than any other mod.

The other issue that often gets left out is cooling. Due to the difference in expansion rates between the aluminum rotorhousing and iron side plates, and to the temperature gradient around the engine, very large forces can result from high engine temperatures. You will find that most reliable high power engines have a very effective cooling system, and most engines that made good power but blew up were running higher than normal water and/or oil temps at the time they failed.

Everything else is just added safety against failures of the above systems.
Obviously you need adequate fuel, an appropriate turbo, and etc. as well but I am assuming you already know that.

Currently at 375 trying to get atleast 550

RE, dei is the dynamic effect intake. I've only ever seen it in stuff about my s4 na. But, I think the s5 vdi may be classed in that as well, don't really look up much on the s5 though so not for sure.