Chinese Firebelly newt out of water-wont go back in

My Chinese Firebelly newt, Newtsie, is usually very aquatic since I got him in 2010. Only getting out on a little floating dock once in a great while for a little while then back in the water. He used to like hanging out in some fake plants I had in the water. I recently took him out and put him in a container with some of his tank water while I cleaned his tank out, like I've done many times before. But when I put him back in his tank on his floating rock dock, he stayed on it and has not gone back in the water. He dips in at the edge/slope of the dock going into the water but then he's back out onto the dry area. One other time when I was cleaning his tank, I moved around the arrangement of his rocks, plants and hideyhole and he didnt like that. He wouldn't go in the water and I looked it up online and saw somewhere(maybe on this site) sometimes certain animals don't like their environments changed, so I moved everything back to how it was and he went back in the water a short time later. I never moved his stuff around after that. I used to feed him in the water and this time around with him not going in the water worried me. I checked on the forums here and someone said to be giving him worms by tongs on land. So I went the store but all they had was huge nightcrawlers or red worms, so I got the red worms and cut off pieces for Newtsie. He won't eat off tweazers, but he showed interest in the worms when I set them down on the land and he ate the chunks up. It was relieving to see he had an appetite and was eating. He was getting quite thin. Other information: I checked his water for PH, nitrates and ammonia to make sure the water was okay for him and since I had just changed it, everything came back okay. So I have a few questions if anyone can answer any or all of them:
1- I'm wondering if anyone has insight why he wont go back into the water like he used to always be in? He doesn't show any signs of skin infections so I'm hoping he is not ill.
2- After reading the forums here, I see he should have more plants in his tank. Other than that, are the rocks at the floor of his tank okay? I had small pebbles but replaced them with bigger stones after learning better. What is a better bottom if these rocks are not good?
3- Does anyone have any feeding tong suggestions that are small enough to feed a Chinese Firebelly newt?
4- I've read mixed messages on this one: some people and sites say that these newts are solitary creatures whereas others say they like living in groups. I had 2 newts to start but one passed away several years ago and Newtsie's been on his own since. I've felt kind of bad but they had always picked on eachother when I had the 2 so I wasn't sure if I should get another buddy for my surviving newt or not.

Thanks for reading and any help you can provide!

I generally let my newts decide whether to be in or out of water and I don't stress too much. I have a colony of chinese firebellies and some prefer their land area, some water.

Live plants are a real boon to Chinese firebelly tanks. Anacharis, Water sprite, Java moss, Brazilian pennywort, Bacopa.. all plants that your newt will love to hang out in; in addition to help keep your water clean. After that, if the newt wants to be in the water; he'll enjoy resting just under the water surface.

If it wants to stick to land after that, that's fine. I have a few that like to be on top of lily pads and water lettuce. You can find good feeding forceps with reptile shops, or I'll cut up earthworms small and put them on the end of a broom straw.

Newts do not need company; they will healthy if alone. That being said, outside of the river newts (the paddletails, paramesotritions, etc. are aggressive and wont tolerate conspecifics ) newts will tend to gather together to hang out. Newts can be gregarious in sharing hiding spots, or a cork float.

Thanks guys for the feedback! As long as he continues to eat what I put down I guess I wont worry too much. Just such a big change from how he was(always aquatic) to all of a sudden NEVER going in the water.

To back up what Otterwoman said, my trio has different preferences as well. Two of them only go in the water occasionally, and the third is never on land.