So I pulled the ECU again and determined the proper capacitor to get, and then proceeded to clean up the gunk. This after trying isopropyl alcohol, denatured alcohol, acetone, toluene, and finally some nasty MEK, nothing even touched the gunk on the board. It is rock hard and can only be scratched with metal tools leading me to believe it isn't something that leaked from a capacitor. My expertise is not in this arena though. Checked the gunk for conductivity with a voltmeter and it was nonconductive, so I'm going to venture a guess that even though it is touching a couple different contacts, it may not be causing any issue.

Replaced the ECU and pulled the IACV to clean it. Looked pretty clean but gave it a good spraying with throttlebody cleaner and let it dry. Replaced the IACV, started the car and the idle sat at 500 rpm. Throttle was responsive, no bogging was occurring and it idled smoothly even though it was only at 500 rpm. Turned the car off and on a few times to cycle the ECU and then let it sit for five minutes before starting again. Immediately idled at 1200 rpm for 30 seconds before settling in at 800 rpm where it has since stayed. Took it out to drive with the engine warm and the car drove perfectly normal and the idle was smooth and consistent at 800. If I sat at a light for longer than 15 seconds, the idle would slowly start to creep back up and if I sat long enough, it would eventually settle at 1100 rpm. So clearly the idle has changed and the ECU has relearned that it should be at 800.

Still no issues with the gauge fuse after spirited driving, and the engine is running smooth, but obviously I now have a small idle issue? Should I drive the car for a few days like normal and see if it sorts itself out? If it doesn't then I'll search the forum for how to adjust idle and other things to check. I know I'm being nitpicky at this point but I would hate to ignore something minor and have it turn major. Thanks for any advice!