The flare of the 350 is about “half” what you would do in the 330 and the 350 has an “autoderate” function - you are supposed to release the sidestick at mainwheel touchdown (FCTM Landing technique)...of course the reality is that most pilots instinctively do their own derotation in my experience. The 350 has more rapid response rates that seem to be built into the Prims and this makes it very twitchy, especially during crosswind landings - on calm days it flies on the rails - very smooth. Pilots who tend to overcontrol the 330 have a hard time on the 350 as a result.
With regards your last question on VREF vs VLS, could you expand on what you are really asking?
VLS is an Airbus term and on approach is typically 1.23 x Vs1G which is lower than a Conventional aircraft which has a Vref of 1.3 x Vs1G. This is because the Airbus FBW has built in low speed and high alph protections and the regulatory authorities approve Airbus’ assertions that a factor of 0.94 x 1.3 x Vs1G is appropriate as an approach speed.
Not sure if that answers your question, hopefully someone more “tech savvy” can answer.