I am wondering if R803 should be left in the circuit, because electricity takes the path of the least resistance.
Where did you get that preposterous idea?? Electrical current flow takes *all* parallel paths, which is just as well because otherwise nothing electronic could ever work; these all contain multiple parallel paths of differing resistance. Besides, R803 is part of a series circuit with respect to battery current flow, so either way is part of the only current path. Its only purpose is to limit current flow into a NiCd/NiMH battery which is charged with a simple constant current concept. Replacing this resistor with a diode just means the current can only flow from the lithium cell to the RTC.
It's perfectly legitimate to replace R803 with a small signal diode.
Here's the
schematic of the A2000 RTC.
As I mentioned
here you need to make sure the diode polarity is correct. If replacing R803 with a 1N60, you need to make sure anode side goes to battery + and cathode (stripe side) to U801 pin 18.
Use a DC voltmeter to check you have >2.5V between U801 pin 18 and ground (computer chassis) with the computer off and the battery fitted.