Here is a photo of the area, am I missing something that is out of the ordinary as a whole?
The next step will probably be to take it to an auto electrician that deals with older cars.
Looks fine but the RCM issues are internal so not visible. The "no crank", when combined with an engine fan running fast after about 30 seconds, is 100% a bad RCM, period.
The fact it would not engage the starter but the fan did not run means that you didn't wait long enough for the fan to come on, or the fan motor/FCM is bad (as well as the RCM), or system voltage is too low.
If it were me, I'd order an RCM and send the "bad" one to DJ for rebuilding.
Also, there is no such vocation as 'auto electrician'. I wish there was, but no one is learning, and no one is teaching, vehicle electronics these days. Not at the "technician" level.
If the starter engaged, I'd point to the Crank or Cam sensor. WIth the starter not engaging, I'd point to the RCM, cept that a failed ECR in the RCM will cause no crank/no start as well as a fast fan - IF the fan motor and FCM are OK, if they aren't then you wont' get a fast fan, even with the RCM being at fault.