You say jumping is very valuable, as a competetive player I cannot disagree more. Jumping is only good if you actually know it will help you dodge fire, say jumping over a rocket. However, jumping opens you up to predictive fire, having a user shoot ahead of you, fully knowing where you will land, just because you jumped.
Also, you choose one of the worst custom maps to show as a TF2 map. Battlecreek should stay in halo, and go nowhere else. Battlecreek offers minimal cover outside the base, and has extremely confined spaces inside the base, seriously limiting realistic play for many classes, and giving serious advantage to others (soldiers, demomen, hwguy). How about cover for snipers, or engineers, or medics? Pick a real custom map, like mach2.
Additionally, your statement of the sentry position you mention for battlecreek being a good one, is inaccurate. It is good, for that side of the map. The Battlecreek map is wide enough that someone can simply go to the other side of the map, and fire at the sentry, and safely be outside the range of the sentry, and have full head-on view of the sentry and engineer. This is probably one of the best spots on the maps, but only because THERE IS NO COVER ON THIS MAP.
Additionally, putting players on a point that was partially captured by an opposing team only works on certain maps. This only works on Well and Granary style CP maps. The rest are unaffecsted by having players on them, they will go down at the same rate. Why is this? Because the only reason you are accelerating the descent on Well and Granary is because you can capture that point, on the other maps it is your job to defend that point, you already own it, and once you lose it, you cannot recapture it that round. Oh, and no matter how many you have on there, it will go down at the same accelerated rate until you start capturing it in your color. HOWEVER, it is good advice to have people to stay by the point, if you are on the point as well as your opponents, even just one of you will prevent them from capturing it at all.