Will i definintely need a 4wd to travel around daintree/cape trib and up to cooktown?
As far as I could tell you can drive north as far as Cape Trib ,after that the road does turn rather primitive. I went about 200 meters on it in my rental 2wd then turned back.
But with a normal car you can drive around the Daintree- there really is only one major road. Make sure to take the fauna walk with Pru- she does the walk near Cooper Creek. She is like 70 and is wonderfull..it is a great 2 hours. Any lodging place in the Daintree should be able to book this for you.

Up until a short time ago a hire car could only stay on bitumen which finished at Cape Tribulation. I have a feeling that the bitumen has now been continued as far as Cooktown but you would have to check.
The road itself was not too bad (dirt) when I went over it 2-3 years ago. (The inland road via Lakeland might be all sealed now - was not then) However, there are 2 creek crossings which might be difficult, and a couple of VERY STEEP sections - 1st gear needed in a Pajero. Seek local knowledge - maybe phone one of the hostels at Daintree.

The inland road via Lakeland (Mulligan highway) is now sealed all the way to Cooktown so is OK in a conventional car. The road from Daintree to Cooktown (Bloomfield road) is definitely 4WD for the reasons stated by #4.
A couple of years ago I hired a Mitsubishi Outlander (soft 4WD) from Europcar in Cairns and they were quite happy for me to take this on the dirt from Daintree to Cooktown (I declared my intended itinerary up front to avoid potential problems). Conditions were very slippery after a fair bit of rain, but the vehicle handled it well.
From memory, the lease conditions did not permit us to drive beyond Laura, but this gave is a good chance to explore the Quinkin (spelling?) sites.
In the dry you'd probably make it easily enough in a large 2WD, but you would be risking underbody damage and, if the car were a hired one, in breach of your lease conditions.
