One thing I've noticed is that the match clock can sometimes affect the outcome of the game. For example, in the ESEA season 4 playoffs, Loaded beat Strickland Propane on Yukon 3-2. However, when the first half ended, Strickland Propane was literally seconds away from winning a round, which resulted in them starting the second half a round behind and having to play catch-up for all of the second half.

In some cases, the clock matters more than others. Obviously, in games where neither team hits the win limit, the match timer is ever more critical. At a bare minimum, most matches don't resolve within the first half, meaning that the game timer could mean a difference of one round.

Going over the rulesets for various leagues:

CEVO and ESEA: 30 minutes per half, win limit for first half is 4, win limit for match is 5
TWL: 20 minutes per half, win limit for first half is 4, win limit for match is 6

TWL's timing is such that in the event of a relative stalemate between two evenly-matched teams, the winning team could conceivably try to do cheeky things like bring things to a stalemate after gaining a lead to win 1-0. This is still a possibility in CEVO and ESEA, but the matches' increased time limit makes it a bit more risky.

Even if teams aren't playing the clock in manners as deliberate is this, there is the question of what transpires at the end of the first half. If there are only a few minutes left on the clock, the team that is attacking will probably want to do everything within their power to use their advantage to take a round during that time. Things also become interesting for the defenders, who will obviously be trying to prevent that. One of the things the defenders have to consider is how to approach that kind of situation, like possibly running one or more engineers or heavies. What are some interesting ways that teams could try to take advantage of the clock to play the score in their favor?

Aside from the things you mentioned, one of the interesting uses of time management is playing purposefully slowly mid-half when you're leading. If you're a round or two up with 15 minutes left in the match, you may as well take your time moving off of mid. Do tiny peeks, only push if you get a lucky pick, don't expose yourself. You can abuse the fact that the other team will be forced to play more aggressive if they don't want time to run down, and we all know how pushes from 2-3 with even ubers and picks go. The success of your attack on 4 or 5 can be greatly increased if you get some picks due to the enemy team's forced aggression. Similarly, you can refuse to push from your 1 or 2 until you have such an overwhelming advantage that success is guaranteed.

Looking at this another way, it may be worth it to purposefully die at times to trigger a push or to lose a round. Fighting 4-5v6 with the 6 players pushing may be preferable to fighting 6v6 on an unfavorable push (though I honestly can't think of any situations where I would ever call for this). Losing a round means you get another chance at mid, which may translate into more rounds won than if you had tried to push from your 1. That is, as long as the enemy team isn't a bunch of dicks and they don't decide to just turtle their 2 at the start of the round.

In practice, the mind-games here don't go this deep at all. Usually a team is winning because they're playing better, so trying tricks like dropping a round in hopes of winning 2 consecutive mids (and rounds shortly after) or forcing a push by suiciding a player generally don't work -- the other team can just widen their lead with them.

Thankfully, no-one cares about this kind of thing in scrims.

If you have 4 of the points under your control, you could always purposefully not push. They will have to push in out of desperation (which they likely won't do right away), and either you can backcap (either winning a point or making them fall back), or you can still have 3/5 points. Although, as Sigma said, if you're winning, these mindgames are hardly necessary.