Everything dwight said about the Rifas is, as usual, correct. the only difference i might add is that while they aren't as important as they once were, and you can definitely to run your system without them (which is preferable to smoking up your whole house), i do suggest not leaving them out of the circuit design permanently. X2's are super cheap so order some from China and leave them out while you work on things. If you start leaving them out on everything, you just might start getting odd behavior with certain older tech or tech that uses the powerline for various things (like powerline networking devices) so best to try and put them back in to avoid that variable when you have other issues.
As for the HF capacitor, i doubt the capacitance will make a huge difference with such a small number. The only thing i would suggest is possibly a higher voltage capacitor. It doesn't *need* higher voltage but that stupid fanless mac design will get hotter and a thicker capacitor will be less affected by the heat and less chance of the esr going up to unacceptable values. I believe one of those manuals mentioned something about that as well.