LUX City/Mosel/Rhine Itinerary for 2 nights/3 days via car...thoughts/suggestions?

Your trip is pretty rushed.

Bernkastel and Cochem are great places to visit. Traben-Trarbach, not so much. You're severely shortchanging Cochem I'd say, trying to squeeze it in between biking and Burg Eltz. The falconry show at the castle is very worthwhile, as is the view you get from up there.

I don't necessarily think a time-consuming boat ride on the Rhine is that important - it will take you nearly 3 hours to reach Bingen, then you have to return to St. Goar by boat or by train for the car. You can drive by this same part of the river in about 30 minutes on the way home. Rheinfels is kind of marginal too, but it doesn't take long to see.

Probably better to spend your time in some of the towns. Take a walk around Oberwesel's old town wall and a walk along the cliffsides in Oberwesel and/or St. Goar. Great Views. Boppard's and Bacharach's buildings are excellent. And if you really want to tour another castle, visit Marksburg in Braubach (across the Rhine and north of St. Goar.)

O'wesel wall
Boppard building w/ walls from Roman times
Boppard tea house
Boppard riverfront
Bacharach
St. Goarshausen wine museum and tasting room in the old city tower at the south end of town
View of Loreley and Rhine north of St. Goar from clifftops
Marksburg Castle

This amazing open-air museum is like time travel and (almost) on the way back to K-town from Bingen:
Bad Sobernheim open-air museum

It was a little bit cool to see Patton's grave, but I'm not sure Luxembourg merits the detour, all in all. If WW II interests you it is possible on your route to Trier to chase down some Westwall bunkers and "dragons teeth" (concrete anti-tank structures.)
B-Werk Besseringen
Dragons teeth, Saarbrücken Take footpath at end of Harthweg.

We were on the Mosel and Rhine in September. I agree with Russ. You're packing a lot in. Bernkastle-kues is very cute. No housing recs from me. For wine, sometimes you can get a variety of small glasses in a restaurant. Skip Traben-Trarbach and biking. Head to Cochem and burg Eltz. We stayed in Bacharach and loved it but Russ has good suggestions.

Burg Rhinefels is my favorite castle on the Rhine. Give it a couple of hours to explore, then go jump on your ship and ride it to Rüdesheim or Bingen, then train back to K-Town. Take your flashlight aps for exploring the tunnels. I like this one a lot better than the Marksburg, be we all have our favorites for different reasons.

Yes, the ship takes a few hours, but it is very relaxing and beautiful. There are those that feel that it is boring, but even though I have done this trip in both directions multiple times, I have yet to find it boring. The many castles, vineyards, clouds, sunshine, the other ships, the birds, all make it beautiful and interesting.

Just to clarify... I like the cruise too. It's relaxing, scenic and interesting for around 90 minutes or so. But after that... well, "boring" might not be the right word, but you do begin to realize you're floating right past some very cool towns and castles and that you will have scarce time to investigate them because you've invested too many hours in the cruise. Hank's schedule altogether is pretty tight. You still there, Hank? I think your best strategy to do the cruise is this: be on the 8:19 train from St. Goar to the Bingen Rhine Stadt station near the dock (arrives about 9 am.) Then walk to the KD dock, get your tickets and catch the 9:30 boat back to St. Goar (arrives there about 11:00 - it's significantly faster in that direction because of the strong current.) The morning will be mostly gone but you'll be back where your car is and still have time for Rheinfels castle and other options as well.
Of course once you arrive on Bingen's riverfront, you may want to just hang there and take in the views:
Riverfront cafe, Bingen
Ehrenfels castle ruins and the island-bound mouse tower just downstream (north) from Bingen
Rheinstein is just to the north as well - a cool spot to stop on your drive back to K-Town.

Thanks for the input folks!. I think your all right about the trip being a little rushed. I wiil probrobly not go to the American Cemetery and pass on the bike riding, T-T and also up in the air about Trier also. Might just make it all about the Mosel/Rhine/Villages/Castles and not as rushed. May end up stopping in B-K and spending the night in Cochem since not going to LUX. Russ I really appreciate all the attachments also. I also like your idea of training down to Bingen on the boat back to St Goar. Kids have never been on a train ride and may enjoy that.

Thanks for the input folks!. I think your all right about the trip being a little rushed. I wiil probrobly not go to the American Cemetery and pass on the bike riding, T-T and also up in the air about Trier also. Might just make it all about the Mosel/Rhine/Villages/Castles and not as rushed. May end up stopping in B-K and spending the night in Cochem since not going to LUX. Russ I really appreciate all the attachments also. I also like your idea of training down to Bingen on the boat back to St Goar. Kids have never been on a train ride and may enjoy that.