Silicon is usually really high on Subarus engines when they are new. It's from engine sealant and is nothing to worry about. It will take several more OCIs to go down to normal levels. If you had 100+ ppm of silicon dirt in your engine, your wear metals would be much higher than they are. On some of these engines, excess sealant can break off and end up in the sump and clog the oil pickup screen, so checking the pickup screen with a boroscope at your next oil change might be a good idea, especially since you're not guaranteed to get warranty coverage with your mods.
Fuel dilution normally ranges from 2-4% on these engines, so you're at the upper end of what's normal for a stock engine. The HPL PCMO 5W-30 has a fairly high HTHS of 3.26 cP. As long as your oil temperatures aren't getting really high, I wouldn't worry about it being too thin even with the fuel dilution.
Aftermarket tunes will flow more air, and hence inject more fuel, and they run a bit richer than stock as well. A small amount of increased fuel flow at high load and rpm can cause a large increase in dilution. Any additional fuel is injected while the piston is low in the cylinder, and the fuel sprays onto the lower cylinder wall, which is relatively cold and allows fuel to condense more easily. The COBB OTS tunes advance the fuel injector timing at high load/rpm, which at least partially compensates for this, and your tune is probably similar, but you'll probably still have more dilution with the tune if you drive hard regularly.
I'd love to see some WOT logs of your tune if you have any you can share.
