PhilipG,
Perhaps I can help here. Two items - VL performance and SRVL control.
F-35B had a hard requirement to be able to land on a ship using a VL with a specified internal ordnance load (two 1000b bombs an two AMRAAMS - about 3,600 lbs) plus enough fuel for a 'wave off' and a go around, at night. That requirement was set against a US specified 'tropical day'. This was a Key Performance Parameter (KPP), so had to be met. And it was, once the programme had sorted out the aircraft's weight in around 2004-6.
The UK, who had originally signed up to the above requirement, then added a more demanding requirement, to be able to recover to a ship at higher temperatures and lower pressures, which equated to summer at the northern end of the Gulf. (ordnance load and fuel requirements unchanged) These conditions became known as the 'UK Hot Day'. SRVLs are the way to meet this requirement.
You might be surprised to learn that very few combat aircraft, land or sea based, are designed to be able to land with anything like a full ordnance load. The designers will assume a maximum landing weight which is always MUCH lower than the aircraft maximum all up weight (MAUW). Many current combat aircraft have to jettison stores or fuel to land on a ship (including cat and trap) and most land base combat aircraft have landing weight restrictions. As an example, the Tornado couldn't land at all with its JP233 weapons fitted.
F-35B has certainly been cleared for a variety of external hard points, but you are correct in that I've not seen any aircraft with pylons or stores doing VLs yet. I would guess that the Pax River team are working through the VL regime on these as we speak. Very extensive computer simulation, wind tunnel and scale model testing has been carried out on F-35B vertical landing aspects, and this will reduce the risks associated with such recoveries.
SRVL software - the aim of the programme was to use the existing flight control modes (and cockpit displays) as far as possible. Remember that SRVLs are a required manoeuvre for the USMC to short strips, and have been cleared for use in service. Work started on SRVL ship landing capability as far back as 2004, but the UK's indecision on F-35B/C procurement between 2010 and 2012 led to delays in the later stages of this work.
You're quite correct that it's not been tested on the ship yet, but as NoHover reasonably points out, the ship's not at sea yet. But it's certainly being developed and tested using both simulators and development (and production) aircraft. Same as the VLs - yes, risks exist until the final trials are carried out and release to service is granted. That's 'ops normal' for any aircraft's flight test/clearance programme.
Hope this helps a little,
Best Regards to those doing the testing,
Engines.