Besides all the stuff that was teased in the 6 month time jump, I've got some ideas as to what next season can hold. There are some things Marvel can use "Agents of S.H.I.E.L.D." for to lay the groundwork for in the movies. And things that they need to do for themselves.
"FIGHT AN EXTERNAL THREAT" - This is a must. Hydra. Hive. In-Humans. Enough navel gazing. With the show clearly tracking down Daisy, and Dr. Radcliffe's L.M.D. storyline, they decidedly need an outside threat that ties in, but isn't Grant Ward's brain matrix implanted into an L.M.D.
Three threats that I think would work well with the ground work already prepared:
"A.I.M." - Advanced Ideas Mechanics. Introduced in "Iron Man III" with the Extremis formula, which is also the basis for Deathlok's non-mechanical powers. They have a long history in the comics of tangling with S.H.I.E.L.D. and are a Hydra subsidiary, so there are plenty of ways this could play out. Especially if they are a government tech contractor.
"THE SECRET EMPIRE / COUNCIL OF NINE" – This could tie in with the most recent season of "Agent Carter" with the Zero Matter / Darkforce potentially being part of the mystic approach of "Dr. Strange" that is coming out in November. And S.H.I.E.L.D. has already had a taste of Darkforce this last season, so there's that. If they use it, I hope that they include some Hayley Atwell and skip a "corruption within the government" story line.
"POWER BROKER, INC." – Everyone who's not an Inhuman, Super Soldier, or Tech Billionaire in a fancy suit is going to want to be powering up, and Power Broker, Inc. is a good way to explore that. The drugs used to enhance the people had a 50/50 chance of killing or deforming the subject. The other half came through addicted to the drugs, and forced into criminal activities to pay for them. It also is a way to bring in a such characters (discussed more below) of the Unlimited Class Wrestling Federation, Super Patriot / US Agent, and Demolition Man.
"US AGENT" - After the events in "Captain America: Civil Wars", Captain America is definitely on the outs with the US government, and he's even left his shield behind. While Cap's in Wakanda and they can make him another. Replacing him in the Avengers is not so easy. But once again, there's precedence in the comics.
Johnny Walker – US Agent. He replaced Captain America in the late 80's in the comic books. He's a different kind of Cap, more aggressive, more vicious. After briefly serving as Captain America, he takes on the mantle of US Agent and joins the West Coast Avengers.
With only the "Black Panther" movie in 2018 as a natural film for Cap to be in before the "Infinity Wars" start later in 2018, Marvel may want to use Johnny Walker/US Agent to help them move some chess pieces around the board regarding Steve Rogers without having to actually use Chris Evans. As a Captain America replacement, US Agent would not be popular with Coulson. But, he's also class-10 strength (able to lift 10 tons), which can be toned down a little for TV, but still have him strong enough to help with the enhanced threats that they will be facing.
Also, they have a choice of shields, Cap's old one, or the plasma one Coulson briefly showed in Season 3. Why even bother showing that and then never develop it?
"TITANIA" – Crusher Creel, aka "The Absorbing Man" is already part of the show. He has a girlfriend named, Mary MacPherran, "Titania". While originally, her powers are given her by Dr. Doom during "Secret Wars", since Marvel doesn't have Dr. Doom rights, they could adjust this out to "Power Brokers, Inc." and Unlimited Class Wrestling Federation. And she could be what leads him back to crime and puts "Law-Enforcement" back in S.H.I.E.L.D.
"DEMOLITION MAN" – Dennis Dunphy is another Power Brokers, Inc. client, and professional wrestler. He kicked the drugs, and became friends/sidekick with Captain America. He got his @$$ kicked by Titania, and totally developed a complex about it.
"JENNIFER WALTERS" - With all that Daisy / Quake is up to, she's going to need a good lawyer. Sure, Matt Murdock is running around New York, but "Agents of S.H.I.E.L.D." could use the comic levity that comes with the the She-Hulk. She doesn't need to join the team or go on any adventures to be a fabulous addition to the team. Plus, she and Titania have a feud.
"BOBBIE & HUNTER" – The spin off wasn't picked up. Bring them back. Now.
There are also other characters that would / should get introduced into the MCU, and Agents is a great place to do it.
"PINK KREE" - All the Kree we have seen so far have been the "Blue Kree". And, basically, have been the space boogeymen. However, there is actually a pink skinned variety of Kree, also. And they are more populous.
The original Captain Marvel (Captain Mar-Vell) was a pink skinned Kree who came to Earth to monitor us. With Marvel having announced a Carol Danvers / Ms. Marvel movie in 2019, it might be time for laying some pink Kree groundwork. Carol Danvers gets her powers from the pink skinned Kree Mar-Vell, so unless they want that movie to have to cover a lot of backstory, they better start getting the pink Kree out there, and make them not the inter-galactic boogeymen they have been so far.
"SKRULLS" - Also, you can't keep having the Kree running around without eventually getting around to their archenemy, the Skrulls. As I understand it, Marvel does have some movie rights access to the generic "Skrulls", they can't use the "Super Skrull". He is a Fantastic Four villain, and with Fox.
"ORIGINAL HUMAN TORCH" – Back at the Stark Expo in "Captain America, First Avenger", there's a sight gag of a man in an air-tight tube.
That is actually an android, the Original Human Torch, also known as "Jim Hammond". Not to be confused with the Fantastic 4's Johnny Storm. As Marvel's first self aware android, if you are bringing in an LMD element/threat to this season, the Original Human Torch would be an obvious resource to tap. And they could definitely use the fact that he's in the NYPD (not NYFD, I know?)
This is a no no-brainer.
"CRYSTAL" – While I'm not sure of the rights here, she is a member of the Inhuman Royal family. Since that movie has been pushed back again, I think she'd be okay to introduce in AoS to continue the Inhuman storyline. Also, she has the ability to control the four "classic elements" – air, fire, water, and earth (metal). Of the royal family, her's would actually be the easiest to handle on the small screen.
Plus, she's been romantically linked with Ronan the Accuser from the "Guardian's" movie.
But people I don't want to see"
"GHOST RIDER" – I guess Marvel just got this character back, and there are some rumors, but AoS is not where he belongs. Netflix is getting a lot of the characters from the "Defender" team. They tended to fight the more mystic foes. He would fit well over there.
"MOON KNIGHT" – Marvel's whacked out version of Batman. This train wreck of a character should never, ever see screen time. Not even in the back ground of some major battle where he is a glorified extra.
"STARFOX" – His real name is Eros. He's a member of the race called "The Eternals". The Eternals were created by the Celestials from early humans. Later, the Eternals alerted the Kree to Earth, which eventually led to the Kree creating the Inhumans from early Humans. Does that make your brain hurt?
Eros has the power to stimulate the pleasure centers in people's minds (among other powers like flight & super strength.). That's correct, he's the Roofie, Date Rape Avenger. Yes. He's an Avenger.
And guess what? You know Thanos, "The Mad Titan"? Not also is he also an Eternal. In fact, they're brothers. Please don't let this be the reason to bring this mess to the MCU. Do not use Eros as a way to provide background on Thanos, even he is the "Big Bad" of the whole MCU plot line so far.
"BRETT DALTON" – Grant Ward / Hive – Do not bring him back as an L.M.D., even though you may have his brain waves stored somewhere.