Tech and chemical makeup is evolving fast.
1. Not always true. Surface machines, for example, have a mode which is designed for constant plug in. It is a hardware/software setting which stops power from reaching the BMS at certain levels (such as 5-% or 80%). It was originally called Kiosk Mode. Same thing for anyone using a battery backup - they do not get turned off.
2. LFP batteries can and should be regularly 100% charged. At least a couple times a month is best for the BMS. There is little degradation to be saved bu the old 20-80% "rule" and the BMS cannot stay accurately calibrated if not at 100% on a regular basis.
3. Always true. Not so much a physical cooling pad or fan, but use the software settings to actively cool and/or passive cool with a lower CPU load.
4. To me, silly. Why? The advantage of a laptop is to have a built in battery backup. Degradation is most current batteries is as much calendar as it is usage.
Where I am coming from is someone who uses portable computers exclusively. Also rely on LFP batts for our RV. Our Tesla also has the LFP formula. LFO is the easiest on the user, just charge as often as desired, and use it. Not all batts are LFP, so you do need to know what the chemistry of your batts are, and act accordingly (Tesla has many non LFP models, which should follow the 20-80% "rule"). Companies like Battleborn (RV and similar battery supplier) are a GREAT resource.
Our RV has LFP batts, which are always kept at 100% when parked. It is our "lifeboat". After roughly 18 months from manufacturer, they have lost less than 3% capacity, which can be contributed to calendar effect. Granted, I have the ability to keep them at the ideal voltage through an external BMS, but it can be safely done (the always at 100%).