I have spent total of 12 months in Ethiopia. I am definitely not fluent in Amarigna but I know a little.
I can't say for sure that you are wrong, but I have never heard the word "dinat" or "dinesh" as thank you. People say "amesegenalu" or as a formal way you can say "igziabher yistilign ina amesegenalu" which means "god give to you and I give you my thanks".
Ibakh means please to a male, Ibaksh means please to a female, Ibakho means please to a group of people.
The word wat and wet is the same word, it is pronounced closer to "wot". It means a sauce or basically the food you put on top of the injera.
Kai wot is a red lentil sauce. Msr wot is another lentil sauce. Shiro is another wot made of powdered garbanzo beans. Tegebino is a special kind of shiro which if you are lucky is made really thick. Restaurants in Shashemene will always make it thick, but in Addis Abeba usually not.
Msr means lentils
Ros means rice
Dabo means bread
Dinich means potato
Tomatim means tomato
Kaisr means beetroot
Karia means spicy pepper like a jalepeno or chili pepper
Shinkult means onion
Natchshinkult means garlic
Atklt means vegetables
Frafre means fruit
Suquar means sugar
Chow means salt
Ananas means pineapple
Muz means banana
Salat means lettuce that is eaten raw, like leafy greens
Gomen means greens that are usually eaten cooked
Habesha gomen means specifically collard greens
(Habesha means local to Ethiopia, it can be used to describe anything from people to clothing to food, and more).
Injera is the flat bread. Teff is the grain itself which is used in making the bread. The only ingredients in traditional injera are teff and water. Sometimes people make it now with teff and corn "maiz", or wheat "sindy".
Berbere is not simply "spice". It is a specific blend of spices. Mitmita with an emphasis of the T sound is another specific (more spicy) blend of spices.
Bekah? means Enough? to a male. Bekash? to a female. Bekaign means enough for me.
Tafach with an emphasis on the T sound and the ch sound means sweet or tasty. It can be used to say the food is tasty, even if it is a spicy dish. Tafach nu, it is tasty. Tafach nebur, it was tasty. If you don't emphasize the T and Ch enough, some people might think you said Tefash, which means "I have missed you" to a female.
Arif is an arabic word meaning Good, it is used a lot in Ethiopia also.
Wasai means amazing. Wasai nebur, it was amazing. The waitor will be really happy if you tell him this.
Selam means Peace. It can be used as a greeting yes. Selam nu? is a question which is asking the person, Is there peace? It can be asked to a male or female. It is very often used in the ritual greetings, in which several questions are asked back and forth, the end result usually being "Igziabher yimmesgan" Give thankhs to god. Selamta means Greetings. Selam nesh? is asking to a female, are you peaceful? Selam neh? is the same question to a male. Selam nachu? is the same question to group of people. Deyna nesh? is asking a female, are you fine? Deyna neh? is the same question to a male. Indemn neh/nesh? is a question asking How are you? Indemn nachu? same question to a group. Indemn newot? is the same question to an elder.
Selam negn or Deyna negn is the answer, I am peaceful, or I am fine.
I don't know what medhane means. But Alem means the world.
Aleh means there is. So if you want to ask "is there meat?" You ask "siga aleh?" Yelem means there is not. So if there is no meat, the answer would be "siga yelem." If you want to ask for something without meat, "Yele siga". Without sugar, "Yele suquar". With sugar, "b' suquar". With salt, "b' chow". Aleh can also be used for a person. If you are looking for your friend Berket and you go to his house, you will ask "Berket aleh?" Someone will answer you either aleh or yelem. He is here, or he isn't here.
Chmr means more. Chamri means put more. For example the lady is filling your coffee cup but she doesnt put enough. "Chamri ibaksh", put more please. Min ye chmr? means what else? Like if you are eating and your plate is almost empty, your host will ask you "min ye chmr?" and you might say "injera ina gomen chamri". Put more injera and greens.
Buna means coffee.
Shai means tea.
The only word I ever heard used for juice is Juice, I am not sure if there is another word for that, I imagine so.
Wuha means water.
Wetet means milk.
If you want coffee with milk, you say buna b' wetet. If you want coffee without sugar, "buna yele suquar". It used to be common to drink coffee with salt, buna b' chow. Now it is more common to have it with sugar. But you can always ask for salt instead. Tqr means black, the color. It can also refer to plain coffee with nothing in it. Tqr buna.
I hope that helps expand your vocabulary. I kept it mainly to food since that seemed to be your biggest interest.
I highly suggest learning to read the Amarigna fidel. It will help understand the language much better. To do this, it is easy to look up a youtube video of someone pronouncing each character. You can make flash cards equating the character to the sound you hear. That was an idea from someone on this forum (was it Jahcub? I think so) and it helped me a lot.