4) What % of your portfolio the stock
This is the easiest call.
In a diversified portfolio, if a stock is more than 10% of the portfolio, it's likely time to trim. It doesn't mean you need
to automatically cut it to 9%. But you do need to trim.
If the stock becomes too big relative to your entire portfolio, you need to cut back to reduce your risk.
Even if you sell 1/3, you still retain most of the position, while reducing your risk.
If the stock is a sure fire takeover target, then be careful about trimming.
If its a pre-discovery drill play, you have big gains and you don't know what to do...immediately sell 1/3. (I am 0 for 2 on this and lost big gains both times).
If its a legit, high-quality company, you have big gains, know its going higher later and you are torn... sell 1/5 or 1/4.