Any tweaks I'm missing?

Most tweaks are tuning devices--if they actually change the sound, whether the change is an improvement or a decrement, is a matter of taste and the specific implementation in a particular system.  With so many devices, it would be hard for you to even know what these tweaks are doing to the sound.  I think you should start by removing items to see what that does to the sound.  Given the number of devices you have, the possible combinations are essentially endless, but, at least this is a no-cost approach to changing the sound.

In my experience, the biggest changes come from power conditioning/treatment and from using systematic grounding devices and schemes (like the Nordost system).  You don't necessarily need rack space for power treatment, a very good power strip (like those from Isotek) can do quite a bit to improve your system. Power conditioning and grounding devices improve soundstaging and clarify instrumental timbre without dramatically changing tonal balance (meaning sound will almost always be an improvement).  Isolating platforms and feet also change sound a lot, but, because they change tonal balance, the change in that respect can be good or bad.  

By far, the biggest change occurs when you optimize speaker and listening chair placement and do some form of room treatment.  That does not necessarily mean buying exotic traps and panels--it could mean using spot rugs on the floor, tapestries on the wall, movement or addition and subtraction of furnishings. 

To the extent a tweak works, it does so by altering the sound.  That necessarily means that some tweaks will alter at least one aspect of the sound it a way that the listener does not like.  All tweaks cannot result in improvement without some negative effect.  This should be part of the discussion by those advocating the widespread use of tweaks.

I have experimented with power conditioning, vibration isolating platforms, and room acoustic treatment (tube traps, wall treatment) and other practices that can be considered in the realm of tweaks.  Even those things that I thought benefited the sound overall included some trade-off.  How can cleaner AC power ever be a negative?  When I put in Isotek power conditioners, the sound seems more detailed and the decay of notes and acoustic space around instruments seem much more apparent.  But, their is a downside in the sound being a bit "drier" or more brittle sounding and flaws in the recordings have become more apparent.  I like the Isotek conditioners (Titan and Evo 3 sigma), but it isn't all to the good.