Here's my two clips:
So, technically, if I was Rashek, I would probably do exactly the same things he did (since I would have the same mind, body, and soul), but yeah, that's obviously not the point of this question.
If I were Rashek, would it be like I, an Earthen human, suddenly found my mind switched into Rashek's body? Would I have all my knowledge from the books I've read? No, too meta/fourth-wall.
But, would I have knowledge of what would happen if I made the choices Rashek did? But not in a meta/fourth-wall way? Or are we just assuming I would somehow be able to make better choices than Rashek?
Or are we just looking for better choices than Rashek? Without actually considering the implications of "If you were Rashek"?
Assuming we are just brainstorming the optimal plan for what Rashek could've done:
Why not just become a Shard? That would solve the issue that others have mentioned about Scadrial not having the protection of a Shard and being vulnerable to Autonomy and such. I mean, didn't Vin ascend Preservation? And Saze became Harmony? I'd have to re-read those scenes or look for more info, but couldn't I just become Harmony? Perhaps that would require Ruin's release, but I could just do what Vin did - releasing Ruin - and then what Saze did. Not sure yet if Harmony is all that good, however. This approach would basically save Scadrial 1,000 years, no? If we think a Harmony could do better, then why not?
Actually, I don't have as many thoughts - at least right now - as @Trusk'our had above, so yeah.
I do think that it may be worth keeping/using Hemalurgy, if only to get ahead of the rest of the Cosmere (*cough* Roshar *cough*). Although that might just be what causes Hemalurgy to spread...like a paradox kinda? Also, is that Hemalurgy on Roshar? Or something else?
Edit: Feel free to point any mistakes I made.
Edit2: Sorry for the weird intro lol.