Everyone who was active in that last thread seemed to want a keeper, and I don't mind that idea.
I would go for keeper or re-draft.
I think it should be 5-10 keepers (your idea of 8 would probably be perfect), and maybe a 5 or 6 or 7 player minors system.
I would like the "unoriginal twist" of the losing the draft pick you selected them. Spices it up a little.
Contracts can get contentious as some teams make trades just to shed payroll and it causes arguments/fights. So I do not want
Maybe an idea of making the teams use their minor leaguers as soon as they get a major league at-bat instead of hoarding them would be a good idea.