You're first guess as to how to play the Chaffee well is right. Due to its slow (relatively) top speed for a Tier 5 light tank and to its fantastic (390m base) view range, it should absolutely be played as a passive scout early in the game. The reason you get spotted before you spot enemy targets is your equipment. Since you already have a 50% camouflage crew and camouflage paint applied, you can live without the camo net. Take the camouflage net off and replace it with either Binoculars or Coated optics (to personal taste). This will improve your view range even further, allowing you to spot enemy tanks further off more effectively. You'll have to choose your bushes more carefully in order to ensure staying hidden, but your scouting will be much more effective.
The next major thing to know about the Chaffee (and all lights in general) is when to make your break. At some point later in the game (unless your team is already losing hopelessly), you'll have the opportunity to get moving and circle isolated heavies and Tank Destroyers and kill the enemy arty. At this point, you will use your speed and agility to kill slower moving tanks by avoiding their guns and getting around them. This is where you'll do most of your damage to the enemy. The exact moment when you go from scouting to flanking and cleanup will be different for every battle, so you will have difficulty with this initially but will get better with time. This strategy of scout-then-flank is actually how I got my Ace Tanker and Mark of Excellence on my Chaffee.
A couple more useful tricks:
- Activate minimap view/signal range/draw distance markers. Found in the bottom right corner of the main settings page, this will show you how far your view range actually extends, so you have better perspective on what is or isn't spotted.
- You describe popping around a corner or over a ridge to spot people. This is a great idea and a good way to get spots, but if you keep appearing in the same spot over and over, the enemies will be pre-aimed at that location to hit you. Try to go around different corners of a building, or over a different part of a ridge every time and you'll find you get hit less.
Work on map awareness. Know where are the best places to scout, to snipe, and to flank on all the maps you play on. it may seem daunting, but you'll get it over time.
As for Jingles and QB, as I've gotten better at playing WoT I've noticed all the little things you have to do to play well. They may look like they're just yoloing it around a field in their AMX 13 90 or Walker Bulldog, but there are so many complexities that you won't notice until you have the experience playing.
And that's pretty much it. Follow these strategies and you should find that your performance in the Chaffee begins to significantly improve. Not only that, but you'll have more fun, and these strategies will follow you all the way through the American light tanks. The spot/flank strategy is still basically how I play my Walker Bulldog, 2 tiers higher. Seriously though, the Binoculars or Coated Optics should be your first priority. Without those, passive scouting is much harder.
Good luck, and have fun!