when finally, the bull market comes should I sell all my bitcoins and prepare to accumulate from afresh in the next bear market again? or should I keep some percentage to continue the accumulation?
Again, it depends on what you have always had in mind. Everyone will have a different plan. If you ask about me, I prefer selling all in the bull run and then accumulating when the market goes down again because I believe it's better to secure the profits from the previous cycle.
An investment management strategy is required. OK, in my opinion the reasons you give are very simple and make sense, but if someone still feels capable of navigating a market situation that is still vulnerable to what is called a market correction, there are always possibilities that will arise, for example whether BTC will be able to break through in the next 2 days. $30k figure or even a rejection back, But, I don't think it's a big deal for those who are familiar with the market.
There are many things that can still be done in this case (if you really want to survive), for example if they buy and hold their assets for the long term, regardless of current market fluctuations with the current Dollar-Cost Averaging trending pattern, then carry out Active Trading by taking advantage of the market atmosphere well.