I think the proximity may depend upon your village. We had Rainforest Village. Our lounger was in a small beach area near the Fearless River, right behind the Bambu restaurant. There were only 3 other premium loungers in this small area. They were pushed back into little sandy cutouts with landscaping between them. The loungers were probably separated by 5 feet. I don't think they could have been scooted together easily in this area. Other areas were just large beaches with the premium loungers mostly at the back. It could be possible to scoot those maybe. They are heavy though and might require help from the attendant. I didn't see any that were specifically right next to each other, but I wasn't looking either. They may have ones already set up this way, since I am sure people reserve multiple and want to be together. We only reserved 1, since it was just the 2 of us.
They go up and down and have notches to catch at different points. Just like a regular lounger.
I think the shade from the awnings really depends upon what time of day and which direction you face. The loungers near us faced north/northeast sort of towards Cabana Bay but on the other side of the volcano. By midday and afternoon, most of them were not really shady. Ours in the middle was being shaded mostly by a large umbrella. The family at the end did manage to swivel theirs and move the awning down over the front of the loungers a bit. I don't think there would have been much room to swivel our lounger, but I'm not sure. The other lounger was in full sun and the groups that had it on our 2 days were not happy. I think the Wave Village loungers may be better off, because they seem to face north/northwest. Plus, I remember more trees at the back of the volcano beach. This map may help some with the beach locations. I don't think it lists where the villages are specifically though. I am debating on whether to change our premium lounger location for late July. If we get one of the 2 on the same beach as before in Rainforest Village, I think we would be OK. However, if we got the other one on our beach or somewhere else, it could be in a lot of sun. I am pastie and value my shade. The other location that I thought might be good was the exit beach for the Fearless River, called Hammerhead Beach, or the exit beach for Maku and Puihi. Those beaches face north/northwest. Look at the map above the linked one below to see the key better. I was really surprised that the our longer faced north/northeast. You can see the Punga Racers emblem on the map; we sat at the back of the little beach bottom right of that ride and faced toward the volcano/racers. I am used to the sun setting more in the south/west here in Texas in the summer.
https://www.disboards.com/threads/map-of-volcano-bay-cabanas.3607449/#post-57670546
To get your longers, you don't need to go to a will-call kiosk or ticket window. I brought the print out of my email, but it wasn't needed. Go to one of the Concierge kiosks inside Volcano Bay. There's one just on the left as you enter. It gets pretty busy with a long line, but I think all of the info is stored at that one. You can also redeem express pass there and rent towels. I did get the express pass paper tickets/vouchers at a will-call at our hotel; I don't know if I needed to do that though. The other Concierge hut that I know of is across from the Bambu restaurant. Since that's near the Rainforest Village, that's where we went the 2nd day. The line was short, but it took forever, 30+ minutes, to get my lounger assignment

They said they had to get it over the radio, maybe back from that first hut, and that radio traffic was terrible. I hope this process improves.