Hello Richard. I joined late and just listened to your last posting. What beautiful music! It's one of those deceiving pieces that are technically accessible, but musically requires more than a lot of people realize. I agree with the others that you clearly have a very good recording here. The slight timing problems don't bother me that much personally.
Here's my two cents and you may already do these things, but thought I'd mention just in case you find it helpful. Listening closely I can hear the wonderful long phrasing you're employing. I do find myself wishing I didn't have to listen so closely, however. This ties into another suggestion someone gave about having a lighter left hand.
Please don't laugh if this sounds ridiculous, but what I often do for these sorts of delicate, lyrical pieces is to step back and play the melody alone - in this case the RH mostly I believe. This lets me focus on the "singing" and shaping of the melody without the distraction of the left hand. Depending on the music, I picture a symphony in my mind with perhaps a solo violin, or maybe a soprano, whose notes rise above the orchestra to deliver the story to the audience. I will play right hand only until I feel I have worked out (or reminded myself of) all the phrasing, dynamics, and sound quality I feel is needed to give the melody its best opportunity to make an impact. In your song it would be "da da Da Da DA Da da" (didn't you like my singing??!!)
For me I always have to pay careful attention to getting the right sound. Am I attacking the notes a bit too hard? This happens to me ALL the time when I play my recordings back... ugg. For legato phrases, I focus in particular on the transition between notes imagining that I'm NOT playing a percussive instrument and instead am carrying the melody under a steady breath as a woodwind player may do. These images help me get closer to that magical, light, pulsing touch that you hear on the youtube link Monica posted. This would close the gaps in your phrase ... perhaps "da.da.Da.Da.DA.Da.da" now - closer but slightly connected. Yet sung under one breath ... so to speak.
In the same manner, I consciously decide how soft I will play the RH melody (at the beginning of a phrase for example), which tells me in most cases that my left hand will need to play even SOFTER than that. Easier said than done for sure, and I know I'm generalizing a bit but I think you get the idea.
My old [Russian] piano teacher from a few years back, Dr. Anna Arshavsky, kept my mind full of metaphors - I think she had a new one for every piece we played!
I was thinking about her recently as I was re-learning a Chopin prelude (No 21). You are probably aware, but this slow waltz begins very lyrically in the right hand, but has a "restless undercurrent" of legato double notes in the left. For this prelude, a very light and legato left hand is critical or it becomes VERY distracting to the melody. Anyway, my teacher really had to work with me because I would start to revert back from my delicate LH. She would grab my fingers and shake them gently, tell me to "relax and forget about using any muscles." She told me (in broken English) to "think of stream; water trickling down; takes no effort; very gentle; don't use your finger muscles" (Lot's of interesting things there to say the least!)
Again, I'm no expert but just thought I'd share my approach in case you can apply anything to your Grieg Arietta. I really think it sounds very nice as it is, but if you enjoyed Gilel's performance you could certainly make some adjustments in that direction. Very light left hand would let the phrasing you've worked out breath. Focusing on the melody may present you with opportunities to make it more connected, more lyrical. I very much look forward to see how this ends up - I really like the piece.