Been discussing this on a website of the professional team I support this morning.
IMO the first challenge is a red all day long for blue 5 & I think if the ref had done that then the rest of the game may have panned out differently.
The second one (where the assistant gets cleaned out) I find an odd one to show considering the tone of the article as, from the direction the assistant flags he's given it against the Woking player
The third I think you could sell either a yellow or a red - I've heard it described as an "orange" but my coach has also said that if that (i.e. I could sell either) is your first instinct then send them off. It's hard to believe that no free kick at all was awarded but I think the assistant could have provided assistance on that & its nearer to him, the contact is on his side & he gives nowt. As a ref (albeit at a lower level) who works with assistants I'd have suspected a foul & looked to my assistant to lead on awarding it, if he doesn't then I may be inclined to think my view of it has made it look something it isn't
For the fourth incident, the stamp/step back is inexcusable but I've seen that clip a few times now & the Woking player has 2 swings back at the Halifax player with his left arm before they end up both grabbing on to each other & falling to the floor. Difficult for the ref to have spotted that from his angle but I'd have given a free kick against the Woking player & a caution for reckless play & then the stamp wouldn't have happened
For the last one it looks to me like they both have hold of each others shirt but in this instance the ref has a far better view of it that the camera & either sees an additional offence or that the Woking player committed the first holding offence. If you watch the ref, he indicates to the Woking player to listen to him & then points to several areas of the pitch & that he was holding his shirt & swung his elbow back so for me I think he's done him for reckless use of the elbow (after acknowledging they both had hold of each other) or that he was a cautioning him for persistent offending (which the footage doesn't show)