RR will always narrow as you reach your target area, and a poor RR is only a real factor if your entry is a bad one, which in your example it isn't, meaning you're applying your secondary risk levels to profit and not initial equity.
That said, from a technical perspective I'm not a fan of fixed value or percentage trailing stops. If you look at something along the lines of Darvas levels, his strategy was to trail with predetermined stops that were based on specific technical levels or price developments, rather than a one size fits all model. This means that his RR strategy was far more adaptable and less likely to see him miss larger moves.
On your first point of trading plans. I can't say I've ever had a plan as such, I have predefined technical models that I stick to, however these change constantly as the market changes. One thing I am a fan of is analysis of trades, even something as simple as charting your own returns and applying filters to that.
I have a number of strategies that win half the time, however applying TA to those figures gets it up to 70%-80%. Knowing when not to trade is just as important, being able to recognise when a strategy is likely to fail is often the difference between being a good or a great trader.
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