Does it melt the decks or not...?

There are many ways to give an answer. Words can be used, with some smartness, to tell a story that, while generally true, hides a few factors.
When F35B went to sea for trials on the USS Wasp, the US Marines needed a success to show to the public and to Congress, to have the F35B taken out of probation and saved from the many threats surrounding it.
One of the things they had to demonstrate during the trials was the resistance of the ship's deck to the F35B engine's exhaust. They had to counter the famous "it will melt the deck!" claim (which, by the way, is born out of a real concern apparent from official documents relating to the F35B development prior to sea trials, and not by an urban legend).

The F35B did not melt the deck, just as the C did not melt the Jet Blast Deflectors on trials. The USMC were also quick, when they released the Wasp trials videos, to specify that the very evidently freshly re-coated flight deck of the LHA had been treated with the usual, standard coatings, and specifically so that, after using the F35B on it, it would be possible to analyze the eventual damages.

 

The trials confirmed that most of the fears were fortunately unfunded, but despite the triumphant claims made by the USMC publically, the DoD documents show that there still are some issues and worries.
The F35B jet blast generates a 75 feet danger radius that must be kept in consideration during all deck ops, and while it does not melt the deck, it does degrade the coatings and paint much, much faster than any other aircraft but the MV-22, which has the same kind of hot exhaust issues, even if the propulsion is entirely different.

The US Navy official announcement at the end of the trials eventually specified that the new coating on Wasp was actually not entirely legacy and standard, after all. Landing Spot 9, used for the Vertical Landings, was coated with a new, experimental non-skid material, the Thermion. 
With the words of the US Navy statement:

Also being tested is a newer non-skid deck surface, Thermion, which is supported by a mechanical bond of ceramic and aluminum that makes the surface more resistant to extreme heat and better endures the wear and tear of flight operations. The Thermion covers landing spot nine on the flight deck, a small area used for vertical landings.

“The Thermion shows no signs of heat stress, which is good for the F-35, and eventually good for all surface ships,” said Kalnajs. [topside design and integration technical warrant for Naval Sea Systems Command (NAVSEA)]

In addition, a series of other modifications were made to the USS Wasp for enabling it to work with the F35B, some of them definitive, such as the re-location of some antennas and radomes, some of them made for prudence and likely to be only temporary, such as replacing the rear Sparrow missile launcher with a dummy one, laced with sensors to measure heat, vibrations, overpressure, and sound levels, to make sure that aircrafts coming in to land won't damage the actual launcher or, worse, cause a missile cock-up inside it.
 
An almost certainly definitive change is the

moving (of) the flight deck’s “Tram Line,” or yellow line, which is used by pilots to guide them when performing short landings, closer to the port side of the ship.

This is due to the larger wingspan and greater sizes of the F35B compared to the Harrier. 
In total, JSF modifications ammounted to 6.4 million dollars in expenditure.

It is fair to expect the presence of Thermion in the deck coatings of the LHDs and LHAs of the USMC in the future, and it would be no surprise at all if Thermion made its way onto CVF as well.
So long as it works, all is good.

The F35 program is continuing to progress in its test and validation phase: one very important news is that solutions to the imagery lag and jitter issues of the Helmet Mounted Display have been engineered and are going to soon be flight tested. A new model of micro-camera is also due to be tested, hopefully solving the problem of acuity of the Night Vision imagery.
These mods are crucial to the success of the F35, which has in its HMD a fundamental component, also due to the decision of having no traditional HUD on board.

The sensors and mission system tests are also speeding up, with the aim of validating the Software Block 2A in the near future. Two-ways Data Link 16, radar, and infra-red targeting systems are all being tested and progressively readied.

So far into this year, both the F35B and F35C are reportedly 20% ahead of their test schedule. We are getting closer to validating the top performances required, with the F35B having flown to Mach 1.4 and having flown to 49.000 feet altitude, so well on the way for the final target of Mach 1.6 and 50.000 feet. It also achieved its expected 7G maneuver limit and validated its maximum airspeed of 630 knots.
The F35B is 50% done through its testing with clean-wing profile.

The F35C validated its 7.5 G limit and flew to 630 knots, but the naval variant requirement is 700 knots, so testing has not concluded. The C flew to 45.000 feet.
It is roughly 40% done in clean-wing configuration testing. Testing with external payloads will have to follow.
In the summer, the re-designed tailhook is due to be tested. 

The F35A is 45% done with its overall test program.

All variants have started flying with weapon payloads, and later this year tests for validation of high angle of attack maneuvers (50° is the requirement) will start. And at that point perhaps we'll have a solution to another cry often heard by people looking at F35 videos: "That's not a fighter jet, it never makes tight turns!".