Let’s see if more people give this round a go. Come on people, try your luck!
The Minotaur, the Wooden King, Skaldak and a Dreg
The Daleks, The Edge of Destruction, Marco Polo, The Sensorites and Planet of Giants.
Grace, Peter the Winder, Tasha Lem, Grisenko, Lorna Bucket, Paris, the Editor, Stahlman and Canton Delaware Everett III (among others).
Dodo, Liz and Ace.
Played by Spencer Wilding.
Probably some common production member.
All guest stars on Supernatural? (I don’t know, never watched the show).
Never got an onscreen departure scene.
It’d help if I actually recognised the characters, etc…
Two. First Doctor stories.
Four. Companions that left offscreen.
Edit: Also, it’d be nice if typing 2 on one line and 4 on the next didn’t show up in the post as 2 followed by 3…
Put a \ between the number and the . to make it not do that
That’s Markdown for you! As @flora_snow00 says, you have to prevent it from thinking you’re doing an ordered list, by adding a slash.
So @DarthGallifrey has 1 and 4 correct but 2 and 3 still elude everyone.
I thought 3 was relatively obvious (hint - it’s the actors involved). 2 involves production personnel…
Star Trek actors
All produced by Verity Lambert? (I’d say all in season 1 if it wasn’t for Planet of the Giants…)
3 Daphne Dare did the costumes?
Nope. But getting closer 
Nope. (I think you mean 2 
)
Yes, I did. Did you see my guess for 3?
One more hint? I went through almost every crew member that was listed on the Tardis Wiki for the Daleks but could not find the connection.
Your hard hint is two
Your easy hint is director
No one else want to have a crack at number 2?
Here are the answers (spoilered in case anyone wants to have one final go).
Creatures all played by Spencer Wilding
Stories with two credited directors.
Actors have all featured in the Star Trek franchise
Companions without a departure scene
Well done to @DarthGallifrey who got two of them (and had the right idea for number 3) and well done to @Tian and @SweetAIBelle who both got one each.