heidelburg, yes or no

Yes.

canceling Heidelberg...unheard of..no!

Heidelburg is a great little town! I would absolutely stay there for a couple of nights. Just because Rick doesn't like it, doesn't mean it isn't a good place to go. He's working on his own tastes, interests, and opinions. I would beg to differ with him on this one!

"...we will be coming from rotherburg on our way to bacharach. any thoughts... danke schoen, nicholas"

(Since you speak a little German... my first thought... it's HeidelbErg and RotheNburg. Burg and Berg, btw, are different words on their own and pronunced very differently from each other in German. The first is like "Boo-uck" and the second like "Beh-uck" - if you're trying out your German at the ticket counter or wherever, the right pronunciation is really helpful for German ears.)

As for the meat of your question: I don't think Heidelberg is a must-see. It's a nice enough town, but there are others that are similarly nice. And the castles near Bacharach are much more interesting and impressive than H'berg's castle. If I had to choose between Bamberg, Würzburg and Heidelberg, all of which you might visit on the way to or from Rothenburg, H'berg would come in third.

Personally I loved Heidelberg and am planning a future return trip. So my answer is a resounding YES visit!
Heidelberg had been high on my list of places to visit, so perhaps that's why I fell in love with the city. You'll find opinions on this forum both for and against visiting. Bottom line comes down to whether it is a must destination for you. Here is a link to a similar question presented to this forum a few years ago which might help you make your decision. https://community.ricksteves.com/travel-forum/germany/is-heidelburg-that-bad

Yes.
Rick needs to revisit this charming town. He was there when the military was there that must have put him off, but they are long gone now. Any town that Mark Twain liked, is worth a visit to me.

I can't understand why so many people hang on to every word from Rick Steve's!!!

He's one man who has his own tastes and preferences, There's a reason that Heidelburg has a reputation as a great place to visit, it's because it is!

Is Rick Steve's the only American travel writer?

I'll throw in another good word for Heidelberg. I liked it so much I went back a second time.

I live near Heidelberg and I like to bring overseas visitors there.
My opinion of the place has changed compared to say 30 years ago. At that time I thought the town had sold its soul to the tourism industry. More or less all the shops in Hauptstrasse, the main pedestrian zone, were mostly selling the usual tourist items.

I am happy to report that this is a different story now. Most shops now cater to the locals and you will also find some individually-owned shops among all the chain stores.

Should you go there or not? By all means yes.
Stroll through Hauptstrasse and soak in the relaxed unique atmosphere created by thousands of students, locals living their everyday lives and a very internationally diverse mix of visitors.
Take some time to look at some of the old houses, visit the Jesuits Church and also take the furnicular to ride up to the castle. Or better still take the furnicular all the way to the top to Koenigstuhl station, enjoy the view from up there and visit the castle on the way down.

Have lunch or dinner in any of the roadside restaurants and do a bit of people watching. In my opinion this makes for a relaxed day with a bit - but not too much - of sightseeing and some time off.
What more do you want from a place you visit as a tourist?

I liked my two visits to Heidelberg, even the one when it was a military town and full of soldiers on a day when the fireworks lit up the castle at night.

Personally I like Heidelberg because of the restaurant "red die grüne Küche" - a vegetarian restaurant at Poststraße 42. Beats all the Tankstelle food on the Autobahn - and just a short drive into town. Other than that, Heidelberg is just a pitstop for me on the way to Baden Baden.