The ladder doesn't mean you have to add 5g from each rung each week.
Basicaly it means start by adding veggies because these are low GI, high fiber, and the least likely to stall your progress. You can add 5 one week, and just keep adding more until you decide you have enough veggies already. Then add a new food. Instead of incrementing 5 with the new food, stay at the current carb amount for a week, that way you can see if it is the food that bothers you or the higher carb amount.
Fresh dairy doesn't just mean more cheese either. Now that you are in OWL you can enjoy plain yogurt (mixed witha ton of different things), kifer, cottage cheese, ricotta cheese, and so on. Some people can't tolerate dairy and it will stall them even in small doses. For them it is best to just skip this rung of the ladder.
Nuts are a good addition. Some people have a really hard time with portion control however. Also they add alot of calories you have to be careful of sometimes. I wouldn't get more then 5-10 of your daily carbs from nuts or nut butters, at least until you know how you do with them.
Fruits are a wonderful step. Berries are low GI and packed with tons of nutrients, they are great to start with. Mix them in a salad, or with yogurt or cottage cheese. They can be added in soon after you move into OWL. Apples, oranges, and other slightly higher carb higher GI fruits may have to wait until almost premaintanance. Again it depends totaly on how you react to them.
Don't look at OWL as such a stressful time or exact science. This is when you get to begin experimenting with your diet and learning more about your body. Weight loss may slow, but you will learn what foods slow you down, and which may slow you a bit but still make for a healthy treat occasionaly