Hello,
I realise I am replying to this forum a little bit late. I hope that you haven't gone on your trip quite yet!
Concerning the Strasbourg / Colmar section of your trip, I think it is wonderful that you are interested in spending so much time in the region of Alsace. It is surely a beautiful destination and much worth taking your time in.
One element to consider is the 'Wine Road' in Alsace. After spending your nights in Strasbourg (I personally would cut this down to 2 - 3 nights), you can take your car and start at the beginning of the wine road. From there, you can meander down the wine road for 4-5 nights, taking your time and staying in new villages along the way.
The advantages of this option are 1) You will get a real feel of the region as you will visit the wine road in totality 2) you will have the chance to visit a great number of magical villages that aren't as well known per se as Eguisheim, but equally worth visiting 3) you won't waste any time due to the uni-directional aspect of your trip. This 'road trip' of the wine road at a slow pace is also great because you won't be doing more than 30 minutes in the car per day.
Do not that the wine road does not entail you to take the highway, but rather to drive leisurely through vineyards.
Here is a map (second photo on the right) of the wine road with quite a few stops listed. http://www.travelandlifestylediaries.com/2013/05/overview-and-map-of-alsace-wine-route.html
As you can see, the villages you plan on doing are all about half-way down, whereas there are lots of lovely ones before and after that. Some of the bigger 'attractions' to visit are also in that first-half of the wine road, such as the Haut-Koenigsbourg and the Mont Saint-Odile (the latter being a one hour drive from Colmar).
If you're planning on doing wine tastings, which I'm assuming is a given looking at your itinerary, some that I really enjoyed last year are Achillé, Domaine Weinbach, and Domaine Mann Vignoble des 3 terres in Eguisheim!
Here is the blog of one of France's most renowned food critics. If I'm not mistaken, he is originally Alsatian, which explains the large concentration of restaurants recommended in the area! I don't see a button to put the site into English but your computer can perhaps translate it automatically or you can weed through methodically with names of restaurants and towns. (you can click on the names of villages in the right-hand column. He also recommends hotels/auberges, winemakers, and shops! ::: https://www.gillespudlowski.com/recherche/0/0/France/Alsace/
I will write another post regarding the rest of your itinerary.