Well I still don't see a probably if we get the ocassionally hero like punisher, moonknight, etc.... maybe they can be going affter someone who shield is going after. And they cross paths. Learn to worrk with each other and bam simple easy way to do crossover heroes.
Then as for powered agents I would prrobably leave only like one or two ie danvers/brand if they show up. So we can keep budget down for overall per episode stuff and fx work go for sfx scenes and any powerred wepons/baddies we get.
As for characters I definately hope they go with mockingbird, carol danvers(in time develop her powered identity), clay quatermain, jimmy woo, sitwall. So we keep the main cast at 5 to 6 members. Another way to save on budget with smallerr cast. Then the ocasional audio/physical/computer appearances of furry/hill when ever jackson/smulders schedules are free.
Then I definately hope maybe they do some pre avengers setting episodes to maybe have gregg clark appear as coulson again. And could be like how danvers, clay/mockingbird/etc... character became shield agents type of story.
As for bad guys we definately should do stuff like resurange of hydra in modern day, attacks from aim(counting on what they arre doing in im3), and also other key shield villain organizations/people. Not to keen on shield specific baddies. So if any one knows some good ones would like to hear who they are.