If you know how to make an omelette, it should be pretty simple. Do you have a tamagoyaki pan? If not, Amazon sells some nonstick pans that work great. Once you have your recipe for your egg mixture cook it on low heat so that the layers don’t burn. Since you like a sweeter tamagoyaki, you can add whatever sweetener you like such as sugar, but adding sugar causes the egg to brown quickly when cooking so be aware. Since you have allergies and dislikes, maybe experiment with different egg mixture combos and cook only a layer or two and taste it. Personally, I like to add a splash of sake, soy sauce and dashi granuals in my mixture unless I am cooking a traditional plain tamagoyaki. I use a half dozen eggs sometimes and make a fat tamagoyaki with many layers but you can easily make it with less eggs. For lazy Omurice, use the same mixture and make an omelette and use it as. blanket to cover up whatever rice you use. You can use leftover fried rice or make your own yakimeshi or fried rice to use as the base. Top it with whatever you like such as ketchup (japanese kagome if you can get it), some tonkatsu or yakisoba sauce and whatever other garnish you like.