Your description sounds 100% correct. Just keep in mind a few things:
- Red and white between the two switches are your travelers. Those are not magical colors, just what happens to be available in a standard cable. So wiring diagrams for the new switches may use other colors or refer to travelers or something else.
- The capped white is your neutral, so if one of your new switches needs neutral and the other doesn't, you will have to place the one that needs neutral in box 1.
- If your new switches have screw terminals, they may or may not match the layout of the existing switches. There is no standard screw configuration for 3-way switches. The new switches should be clear about what goes where, but if one of them is a simple switch and doesn't include directions, it should have two screws of one color and one screw of a different color, and the travelers would go to the two screws that are the same color.
- The Caseta may use travelers to the other switch "as is" or may have a particular configuration - follow the directions carefully.
- Colored tape is your friend. Since everything is black, white, red, marking specific wires based on function can help. The only requirement is neutral = white. Typical (but not required and not universal) is black for hot, red for switched hot, which you appear to already have. But traveler colors can vary depending on configuration. You can use, for example, blue or yellow tape to mark travelers or other particular wires. Always mark both ends the same way.
Update based on installation instructions
- Incoming (from panel and fixture): Black = hot, red = switched hot, white = neutral
- Switch 1/2 cable routes black from incoming hot to common of switch 2, red and white as travelers from switch 2 to switch 1
- Common of switch 1 to switched hot
I believe the Caseta instructions are based on a few assumptions that don't apply in your case. In particular:
- Incoming hot and neutral on a black ("tagged")/white cable
- Switch 1/2 cable travelers black & red, neutral white
- Outgoing switched hot and neutral from switch 2 to fixture black ("tagged")/white cable
You have a "medium" setup. You have neutral in one box (absolutely critical here) but you have white between the boxes as a traveler, not as neutral.
I definitely fault Lutron for using the "tagged" indication for both hot and switched hot. That confused me quite a bit until I realized they are two different, not connected, wires.
Based on the schematic (page 2, as posted at the moment as an image in the question), things are actually OK:
In the Switch 1 box:
- Incoming hot black to Caseta black (disconnect it from Switch 1/2 black)
- Incoming white neutral to Caseta white
- Incoming switched hot red to Switch 1/2 black and Caseta red
- Caseta blue to Switch 1/2 red.
- Cap Switch 1/2 white for safety.
In the Switch 2 box:
- Remove the white wire from the switch. Cap it with a wire nut for safety.
You won't need the yellow jumper.