Replacing two three way switches with one single pole switch, with fixture in between switches

Question

Up front, I do not know what I am doing.

I would like to replace two three-way switches with one smart single-pole switch, in a home without neutral wires. I believe my wiring configuration is best represented (with the exception of the neutral wires, which I do not have) by this diagram

^{Source: https://www.electrical101.com/3way-switch-wiring-using-nm-cable.html}

based on the fact that one switch is in obvious proximity to the main panel and the other is on the opposite side of the room in question, with the fixture in between them. I would specifically like to eliminate the switch between the fixture and the main panel, and use the smart switch on the other side of the fixture.

From what I've gathered from Google results, what's needed is essentially

1. Remove the panel-side switch, and join the line wire and one of the traveler wires with a wire nut; and
2. At the other switch location, attach the black wire (connected to the black screw) to the "line" lead of the smart switch and the "same" traveler wire to the "load" lead on the smart switch.

What isn't clear about those two steps is how to determine which traveler wire at the other switch location corresponds to the one joined to the line wire at the panel-side switch, without trusting the wire colors to be meaningful. I would think I could determine that by turning on the light (from either switch) and noting which of the two traveler wires at each switch had voltage.

My questions:

1. Is my presumption about what my wiring configuration is reasonable?
2. Is what I want to achieve possible given that presumed wiring configuration?
3. Should I be worried about whether doing this is safe?
4. Am I right about how to determine which wires to join together, and which wires to connect to the smart switch?
5. Given 4, do I even need to actually know 1, or would this plan work regardless of the wiring configuration?

Answer 1

If you have that.

At the the first switch location connect the incoming black to the outgoing black. (you could use red instead of black, but why?) cap the unused red. leave the incoming white connected to the outgoing white.

At the lamp juction box, join the incoming and outgoing whites and a short wire together connect that to the lamp. remove any colored (or black)_ tape or paint marking from the white. connect the outgoing red to the lamp, cap the incoming red, connect the incoming black to the outgoing black.

At the far switch clean tape or paint markings off the white wire connect it to switch neutral. Connect black to line. connect red to load.

If you got the two traveler cables swapped, you only need to swap two wires (the reds in the lamp junction).

look for the marking on the white wire that goes to the far switch it should be there, and wioll clue you in as to which is which,

Answer 2

What you're describing is bypassing the first switch and using the second one as a switch loop.

In the first box (which you want to bypass), connect black to black and white to white. Disconnect and cap (insulate) red so it won't cause trouble and is clearly not in use.

At the lamp, connect black to black, white to white, and the lamp between the whites and the right-hand red, which will be your switched hot. Cap the left-hand red.

In the last box, the connect black to the smart switch's Line terminal, white to it's Neutral terminal, and red to it's Load terminal so red can return switched power to the light.

Let me know if that's unclear and I'll post a modified version of your graphic.