I did almost the identical thing you are asking about: 3 nights in Ljubljana and 2 nights in Kobarid, with a day trip to Bohinj and Bled. (Vintgar Gorge was closed when I was there in mid-May because they had very bad weather over the winter that damaged the paths. This was 2014. I ended up visiting Tolmin Gorge, near Kobarid, instead, and it was terrific, and I think I passed maybe one other group of visitors the entire hour-plus I was there.)
I drove to Bohinj via Škofja Loka, which in itself was a pleasant short stop, but the scenery between there and Bohinj was some of the most stunning I've seen anywhere.
Some people seem to like Bled as a place to spend a couple of days. I just walked around the lake, up to the castle and back down, and stopped for Kremsnita at an outdoor cafe. I didn't take the boat ride to the island, which in retrospect I probably should have done. I will leave it to others to tell you if they think staying overnight in Bled is worthwhile.
On the fourth morning, I stopped at Zale Cemetery in Ljubljana (https://www.visitljubljana.com/en/visitors/things-to-do/sightseeing/zale-cemetery/) and at the beekeeping museum in Radovljica (https://www.radolca.si/en/attractions/museums-and-galleries/museum-of-apiculture-radovljica), both stops I enjoyed a lot. Then drove over Vršič Pass on the way to Kobarid, arriving in time for dinner.
If I were going to recommend a plan for a friend who's never been there, this is exactly what I'd suggest.
Have a wonderful trip!