tuck/untuck & shoe recs

This is one of my favorite t-shirts, I got it thrifted a few months ago but I only wear it under an unstructured linen navy blazer/sportcoat for rooftop parties and the like. Just trying to explore other outfits to wear it with. I really like monochromes and that's what I'm trying to go for. Re the t-shirt, I feel there's something weird with the fit around my neck. I like cuffing the sleeves, I feel that it helps. First question is if this looks better tucked or untucked. I have a bit of a belly now (that I'm working on losing) and am 5'7'', to give an idea of proportions. Second question is what shoes to wear this with. Rn I literally only have a pair of black converse and a pair of brown Sperry boat shoes. I was thinking maybe some off-white Club C 85s, any and all opinions are welcome!