Depends between which parts you measure. Less from one finger to another fonger of the same hand, more from head to toe...
More detail in this article.
Depends on where the current flows and of the type of current: AC vs. DC.
Typical RCDs trigger at >= 30 mA. This is considered a limit above which the current can be lethal.
More information can be found e.g. in this article.
Resistance is comparatively irrelevant, it is the current that kills.
Of course, if the resistance is high, the dissipated power is also high as per P = I² × R and this power can add to the killing e.g. by burning flesh, skin and organs.
Better not find your personal limits through experiment. Keep it save, keep away from dangerous currents and/or voltages.
There is no reference to voltage. Depending on the circumstances a low voltage can create a high current (e.g. through wet skin) or a very high voltage can be harmless (e.g. if the internal resistance of the voltage source is very high).
Lastly it is the current that kills, not the voltage.
"It's the volts that jolts, and the mils that kills." A small current will stop your heart beating, but if you have enough voltage AND current, (like, say a lightning bolt), you will turn into a burnt sausage.