It also seem to me that you might get stuck if you had a buying order and the price drops so far down at a speed where you would have liked to stop the existing order and place another one further down.
That's a dilemma everyone faces. You're getting into the weeds of trading now, might be best to start a thread about bid/asks etc. Part of the trick is to anticipate the market and place your orders accordingly, and I find the larger the time-frame (4 hours, day) the less chance you have of being caught by drastic movements. But yes - you might place an order as follows:
● Want to buy at $7000, price is currently at $7200 on a downward trend.
● Price hits $7000 and your buy order gets filled.
● At this point a stop-loss should be placed at $7000 - x% where x is the maximum loss you're willing to incur. So lets say we have a stop-loss at $6800.
● Price falls further to $6500, but your stop-loss sold everything at R6800.
● Price is steady at $6500, you can consider buying back in (assuming signs point toward it resuming an upward trend)
(Luno doesn't have stop-loss options.)
Lastly is the candlestick principles the same for all types of trading, crypto forex and normal jse share trading?
If you're just starting out focus on trendlines & support/resistance. But yes they do to a degree.