I think I may be able to answer your answer your altimeter question. If you're asking how to read the altitude that you're at, WWI altimeters read slightly different than an altimeter in a modern plane, a Cessna, for example.
In a Cessna, the long hand reads the hundreds of feet, and the short hand reads the thousands. So, if the short hand is between 1 and 2, and the long hand is on 5, then you're at 1,500 feet, kind of like reading an analog clock.
In WWI aircraft, there is only one hand, and it reads by the hundreds. So, if the hand is halfway between 1 and 2, again, you're at 1,500 feet. If it's on 4, then you're at 4,000 feet. If it's 2/3 of the way up to 1 (closer to 1 than 0), you're at ~700 feet, etc.
And +1 for Requiem's films. His are the first tutorial videos I've ever seen on Youtube, and the only ones I'll watch, unless he hasn't covered the aircraft in question. He's simply phenomenal. Also, check out his dogfighting tutorials. They'll help out IMMENSELY if you're new to the art of aerial jousting.
Hope that helps!!