The "missing random.seed" message is unrelated to any installation or upgrade problems you may be having. The file is created/written by rc(8) during shutdown, and then read by rc() again during boot. It is one of many entropy feeds to arc4random(4). It is always missing on a new installation, because there was no prior shutdown to create it.
https://youtu.be/aWmLWx8ut20 (video)
http://www.openbsd.org/papers/hackfe...dom/index.html (slides)