What we have done with my son is feed him what we are eating. We started this when he started solids so it might be a little more difficult for you to switch but it will be worth it. If I was having oatmeal, strawberries and coffee for breakfast, he got oatmeal, strawberries and milk.
Since she is already 2, you can explain to her that things are going to change. I would simply stop BUYING all the processed food - breaded chicken, pizza, mac & cheese, goldfish etc. If they are not in the house then tantrums won't work.
When she wants a snack, offer her two options - both healthy ones - say banana or avocado and let her choose. I see nothing wrong with her snacking (you could certainly say no snacks less than an hour before dinner) - if she fills up on green beans and an apple, so what if she eats less at dinner.
We do eat waffles, pancakes and french toast - we make them from scratch on the weekends. That way, when they are gone, they are gone - not available to pull out and microwave. (we do now freeze extra pancakes but DS currently only asks for them for breakfast)
Research has shown that it takes toddlers and average of 12-16 times trying a new food before they will reliably eat it. So keep trying. There is also research that shows that 'hiding' foods (Sneaky Chef approach) does NOT result in kids who choose to eat more fruits and veggies. Also, bribing them to eat a food makes them LESS likely to eat that food the next time it is presented.
Have her help make the food - my son is way more likely to try foods that he 'made' , picked in the garden or selected at the supermarket. At two he was able to mix, whisk, scoop and pour - all with assistance. We also got him a plastic lettuce knife so he could cut soft things. It takes longer to cook with this 'assistance' but it is worthwhile.
We do not fight about what he eats. Since we only put food on his plate that we are happy with him eating - he can eat it or not. We do ask him to try new things when we have something he has not had before - he just does try it. Sometimes he likes it, sometimes not the first time. We do not make him eat anything before dessert. Dessert is fruit and he can have it whether or not he ate much at dinner.