1. Yes, I have been profitable many times but I don't sell all my coins at once.
2. I take profits whenever I am in need of it. The last time I booked profits and bought something from my wishlist.
3. Booking profits is a very important part of investing because if you don't book profits then your investments are as good as nothing.
Your investment strategy makes me quite curious and surprised: usually, investors seek to determine the distribution zone of the market to sell tokens to optimize profits instead of holding and selling them when need money like you are doing.
I usually keep USDT and gradually sell it to fiat when I need money in my life. For other tokens, including BTC, I still only buy and sell according to the market cycle, meaning I try to buy in the accumulation zone and sell in the distribution zone.