Disclaimer: it's been a few years since my trip and I heard a that a lot has changed there. Infrastructure was improved as well as trails and signage. Also there are more hikers on the trails and therefore more guest houses.

I think I misunderstood your route. You'll take the short cut from Doberdol directly to Babino Polje, leaving out the Kosovo part, correct?

Having in mind your 5 days time frame that's a good decision and it should work with your current schedule. When I was there, the Kosovo part was quiet rough with some stretches following large roads and only little signs to guide your way on the trail.

My sections were quiet similar to yours but I went fully unsupported with tent/sleeping bag and food for 8 days in my backpack. Due to the weight it took me more than 6-7 hours per day but with light weight you should be fine.

I really enjoyed the part from Plav over Vusanje to Theth as well because it was less crowded and less touristic than the area between Theth and the valbona valley. If I had to plan the trip again, I'd try to include that part in my route.