I think that Neil was a very realistic character. He was everything Brent imagined himself to be but at the same time lacked much of his heart and kindness behind the facade.
There was something slightly smug about Neil that was very much behind the surface but that audience subtly picked up on. His friendship with Finch was a fantastic observation of human interaction. Finch is a bully and a nasty, intimidating man. Neil appreciates this fact and Finch also appreciates that Neil is someone whom h has to respect and show admiration for.
Smug is the word that fits Neil's flaws more than anything else. So whilst Brent is insufferable at times and hopelessly deluded, as the show reaches it's conclusion we see that Brent is a tragic figure and that in some respects the seemingly perfect Neil is actually a haughty man full of himself.

Neil wants everyone to love him, pathetic.

In a landslide.

The funny thing is that David was the first choice to take over from Jennifer. Neil only got the gig because Brent failed the medical. The board clearly thought David was the better choice despite his antics, it would be interesting to see how he would have done in it.

Neil is patronising. He's friends with Finch and is cold towards David.

When Neil gave David tickets to the Christmas party, he was clearly hoping that David would show up without a date and was disappointed when David's date did show up.

Well he's at a party and not in his authoritative state of mind. He also probably had a drink or two as well.

I interpreted it as he's not that all-out nice guy that people think. It's a bit of an act and he's actually a bit of jerk himself, which seems to show when he's drinking.

Oh, because the regime don't like it!

As far as Brent being his own worst enemy? No argument here.

Not that Neil was infallible, but I see David as swinging the first punch, or series of punches. Neil admitted that it was awkward to be David's boss, after having been his peer, which was an honest remark. David didn't make it easy and slagged off Neil in front of others repeatedly (calling him "pathetic" for playing ball (cricket?) with staff during lunch and wanting to be liked, mocking the cake he made for Trudy's birthday ("too rich," "I prefer a flan"), or his dancing on Comic Relief day. When he was goading David towards the end, I saw that as payback for all the times David did it to him.
I once had to supervise someone who pretty much told me from the get-go that they weren't going to pay attention to my feedback, and I see that same passive-aggressiveness in David. Neil wasn't perfect, but I think he tried with David, and did seem genuinely disappointed during their redundancy conversation. David Brent was his own worst enemy.

The first, while totally wrong, was intended as a joke. Bad idea, but his intention was OK. The whole role model thing was a bully tactic, for sure.

I remember the whole "wake up at the crack of Dawn" thing, but to me, Brent thought he was being funny. To any reasonable person, there's no doubt he was being inappropriate, but I don't think that was his intent.
What about pretending to fire her for stealing?
Or when he forced her to put him down as her role model?

I always kinda felt that Brent was getting ganged up on there, and lashed out almost in self defense. I remember the whole "wake up at the crack of Dawn" thing, but to me, Brent thought he was being funny. To any reasonable person, there's no doubt he was being inappropriate, but I don't think that was his intent.

As I was watching the Christmas Special part 2, I realized that while Neil had always been kind of harsh towards David, I realized some if it was probably justified. David had proven himself unmanageable by the time they fired him, and since he was apparently in the office constantly since his departure, it would create a distraction to the workers.
People seem to overlook this when rooting for Brent. In the Christmas Special, when Neil announces he's getting married, he shows the guys a photo of his bride-to-be, to which Brent remarks:
"I prefer someone a little bit more intellectual"
implying that she's a bimbo just because she's attractive. Brent is just as guilty of sexism as Fichy and Neil, and that's without getting into how he bullies Dawn in Series 1 & 2.

As I was watching the Christmas Special part 2, I realized that while Neil had always been kind of harsh towards David, I realized some if it was probably justified. David had proven himself unmanageable by the time they fired him, and since he was apparently in the office constantly since his departure, it would create a distraction to the workers.

I got the impression that Neil already had a pretty good understanding that the 'Gay' jibe aimed at Brent was exactly the kind of banter that he (Brent) would have no hesitation in dishing out himself so Neil just wanted to get the first insult out there using the type of language that David Brent understands.

Neil is a bit a of a wanker, and a bit of a 'subtle' bully popular type.
His first speech to the staff in Series 2 Episode 1 contains a jibe implying Brent is gay, and that's before they have even got to know each other, so it's fair to say Neil is a bit of a tosser for sure.

Neil is more annoying each time I watch.

Neil is comfortable with everyone, therefore he can engage in serious business talk and sexist banter with ease. It's also implied that Neil is slightly higher class than Brent (accent, love of rugby) the reason why Neil is so tolerant of Brent is because he knows he's much better than him.