Hi, a thorny problem. Unless you can turn around the basic Laws of Physics, there is not much (anything) you can do without making physical changes to the engine, or adding an oil cooling method.
b) Yes, this will keep the oil longer in contact with the hotter parts of the engine. Not what you need.
c) Yes, definitely, BUT you will need to also increase the holding capacity of the engine. Adding more oil will help reduce temps but the increase oil level in an unmodified sump will add other problems with the rotating masses. Excessive cylinder wall coating, piston bypass etc.
d) Don't understand how!
e) If it is an external oil filter you could try adding aluminum fins (anodized matte black) to it and make sure it is in a good air-flow position
f) Add an external oil tank for increased oil volume without raising the current internal oil-level.
g) I have been wrong before!