Here is who I will cast for uncasted characters of the Marvel Cinematic Universe I will also add what films should be in the untitled Phase 3 Marvel movies and Phase 4. I will also be adding X Men and fantastic Four if Fox want to share them with Marvel.
Untitiled Phase 3 Marvel Movies
Fantastic Four and the Inhumans
Black Widow
Phase 4
Fantastic Four: the Incursion of the Skrulls
X Men Phoenix
Spiderman 2
Doctor Strange
Gabriel Woolf as Dormammu - even though he first appears in Phase 3 of the MCU. He will be the big bad of phase 5 of the MCU. Because of Gabriel Woolfs role as the voice of Satan in the Doctor Who episode Satan Pit. I think he will be very good as Dormammu.
Spiderman Movies
James Nesbitt as Norman Osborn/ Green Goblin- James Nesbitt was very good As Jekyll in the 2007 BBC drama of the same name. I think James Nesbitts Green Goblin should be very similar to that of his role as Jekyll.
Steve Pemberton as Otto Octavius/ Dr Octopus
Mark Gatiss as Curt Conners/ The Lizard- The reason I picked Mark Gatiss as the role of the lizard is because of his role as Richard Lazarus in the 2007 Doctor Who episode The Lazarus Experiment. If Mark Gatiss gets the role of Curt Conners/ Lizard. I would like to see him in his wig that he wore for Mr Chinnery in League Of Gentlemen and Young Richard Lazarus in Doctor Who.
Captain Marvel
Hannah Spearitt as Captain Marvel/ Carol Danvers
Avengers: Infinity War
Aiden Turner as James Logan Hewlett/ Wolverine
Fantastic Four and the Inhumans- This film would be the origin story of the Fantastic Four in the MCU. This version of the Fantastic Four will be Inhumans and the cosmic ray that they were exposed to to get their powers in the MCU is terrigan and then their spaceship will crash in Attilan after exposure. The MCU Fantastic Four will be Marvel Doctor Who.
Matt Smith as Reed Richards/ Mr Fantastic
Lily James as Sue Storm/ Invisible Woman - Lily James is Matt Smith's (Mr Fantastic) real life girlfriend, so I think Lily James would be a very good Sue Storm.
Robert Kazinsky as Ben Grimm/ The Thing- In the comics Ben Grimm is Jewish, so is Robert Kazinsky so I think Robert would do very well as Ben Grimm.
Bradley James as Johnny Storm/ Human Torch
Jeremy Piven as Black Bolt
Kara Tointon as Medusa
Hannah Tointon as Crystal
As Kara and Hannah Tointon are both sisters and played onscreen sisters before (Mr Selfridge) I think Kara and Hannah would be very good as Medusa and Crystal as they are both sisters in the comics. Get a red wig for Kara and she would be a very good Medusa.
Matt Lucus as the voice of Lockjaw
Colin Morgan as Maximus the Mad
Black Widow
John Simm as Wade Wilson/ Deadpool- I think Deadpool would be a very good comic relief character in a Black Widow Solo movie if Fox Shares him with Marvel. Because John Simm was a very good master in Doctor Who and can be very funny. I think he would be a good Deadpool
Adam Driver as Victor Von Doom- This will be Dr Dooms first appearance in the MCU, He is not yet the Doctor Doom we know in the comic. in this film, he is a Jihad John style terrorist working for A.I.M and Hydra who threatens to release a deadly leprosy like disease. He also worships Dormammu. In the end of the film he is affected by the disease losing his limbs, disfiguring his face, then he is saved by Hydra and restored using Iron Man/ Ultron/ Chitauri technology and becomes the Doctor Doom that we Know and love. He will not return until the beginning of Phase 5.
X Men
Timothy Dalton as Charles Xavier/ Professor X
Arthur Darvill as Cyclops/ Scott Summers
Amy Manson as Jean Grey/ Phoenix
Freema Agyeman as Ororo Munroe/ Storm
Stephen Fry as Hank McCoy/ Beast
Rachel Stevens as Allison Grimm/ Dazzler- This version of Dazzler will be a cousin of Ben Grimm/ the Thing
Lacey Turner as Kitty Pryde
Derek Jacobi as Magneto
Daniela Denby Ashe as Mystique
Anthony Head as Nathaniel Richards/ Mr Sinister
Dave Schneider as Nightcrawler
Marc Warren as Sabretooth
Billie Piper as Emma Frost
Fantastic Four: Incursion of the Skrulls
Robert Llewelyn as Mole Man/ Harvey Elder (Cameo)
Avengers: Kree Skrull Wars
Nicholas Briggs as The voice of the Supreme Intelligance- As he was very menacing as the Dakek Emperor, he would be very good as the Supreme Intelligance
Avengers:The Wrath of Galactus
Gabriel Woolf as the voice of Galactus- He is the big bad of phase 4 as he was behind the destruction of the Skrull planet (Fantastic Four:Incursion of the Skrulls), the planet of the Symbiotes (Spider-Man 3), The Shiar planet (X-Men) and the Kree planet.