Whether you're starting up with a small amount of capital or you have huge amount of money (i.e your life savings) to invest in Bitcoin. It is key critical for you to understand the nitty-gritty of Bitcoin and to know at what point in time you should invest and at what point you should withdraw is very vital.
As an investor you need to learn the stop loss habit to learn how to stop an investment when there is an uptrend or downtrend in the market not just being over ambitious or greedy in the investment.
I'm finding it hard to understand your points because it seems you are mistaken buying and holding for trading because is only traders that uses the concept you are talking about because actually I don't see the need why an investor whom intend to buy and hold should be concerned on selling there investment if the Bitcoin price is up, so perhaps if your intention is for holding you shouldn't be monitoring the Bitcoin price direction but instead you should always focus on accumulating Bitcoin because that's the only way you could be free from emotional trauma of possibly losing your investment for trading because of greed