I'll piggyback onto Kyle's excellent post, and crunch 1-4 together:
When I taught FF I separated stocked and wild trout bc they can provide very different lessons –wild trout taking you deeper. We started on recently stocked trout to learn basic skills and moved to "wild/streambred" trout ASAP bc this is where real trout fishing begins; learning how trout behave in relation to the complexities the natural world dishes out. This compared to what factory raceways, or overly managed/artificial fisheries, do.
The very basics are:
-Water temps below 70F, under 65F for brookies. Short windows with higher temps trout can survive but not often prosper in. These waters/areas are called marginal habitats. Trout respond by either moving, adjusting timing of activity, or if other options aren't available stay and tough it out.
-Seasonal habitats are important to identify and find. Trout migrate to and from them. How far depends on proximity, previous habit, and genetic predisposition. On some streams trout move a great distance, in others they simply slip up or down a ways. General movements tend to be up the watershed for summer and spawn, and down the watershed for winter. But this is not always the case. Your eyes and thermometer will clue you in.
-Spawning gravel with little silt load (almost always associated with ground water, esp so for brookies).
-After this growth rates are a balance between temperature, and food supply for all size classes.
Individual streams vary widely in what they offer in terms of survival, reproduction, and growth.
Trout can move a great deal, seeking better conditions. The less stable the environment (temperature and food) the more trout are apt to move. And they can move quite a ways. A good perspective is NOT to look at a given stretch or stream but the entire watershed. Some areas only hold trout seasonally, and this can parse out in terms of trout size/maturity too. Over time, naturalized populations become valuable bc they've "figured out" how to survive, even prosper, in that given watershed or subset of it. Thus, streams can vary "culturally" I suppose, requiring diff things from the trout within. If you know the basics, and put in the ground work, you can figure this stuff out. It's very satisfying to have your finger on that pulse, not to mention the great fishing you can have all to yourself.
Great questions. If you keep your head in the game, they will never end.
Oh yes…Technical fishing –is usually meant to describe difficult waters, usually applied to flat, heavily fished, food rich tailwaters and “spring creeks”, where fish are difficult to dupe. A wider view is anywhere your standard chuck-n-hope (EHC caddis all day) fails and you have to start thinking, adjusting, and often start looking at all aspects of your fishing from offerings, presentation, and knowing and applying the technology to get there. Takes knowledge, flexibility, creativity, perseverance, delayed gratification, flirtation with the limits of sanity, etc… you know, all things that define intelligence. Welcome to the real world. :)