After going through some of the engineer videos, I realized that you do not cover 5CP, KOTH, or CTF. 5CP requires a minisentry-based loadout for the engie, as your team that has been defensivly resisting enemy pushes can suddenly go on offense. It also requires a good knowledge of where the ammo is, because it's much faster to destroy your dispenser and replace it on the next point than it is to try to carry it all the way. KOTH also requires a minisentry-based loadout, and has less emphasis on teleporters than other gametypes, simply because the maps for the gametype are so small. I'm not saying they're useless, just that you should try and judge when and where a safe, generally unpatrolled place for your teleporter should be. CTF is different. Teleporters are generally useless because the entire map is constantly visited (unless you somehow managed to put one inside their intel room). Sentries are top priority here because no one on your team will have the attention span to constantly defend your intel from inconsistent attacks. Dispensers near the front line are important to keep up the attack.

Anyone else have other thoughts on the Engie?