Normal lines are not redrawn. Dotted lines repaint, but do not affect trading (do not affect backtests). You can turn off repaint in the script settings. Repaint (dotted lines) are needed only for clarity. To make it clear from which bar the level is created.
Lime lines above - level from a local high bar. To open a long position. Using a market stop order.
Red line at the bottom - the level from a local low bar. To open a short position. Using a market stop order.
You can trade without short positions. Then the red line is the level for a stop-loss order.
Reverse trading can be used. Without stop-loss orders.
Order size depends on the risk size parameter and possible loss. If risk size = 2%, it means that the loss will be no more than 2%.
Symbols: XBT/USD, BTC /USD, BTC /USDT, ETH/USD, etc - need USD(T)
Timeframes: 1h, 4h, 1d