Shopping,
As a BT myself, I hear a lot of what you’re saying. But think of the other side.
It says that chometz “should not be seen or found” during Pesach. That means you if you can’t see it, you could still not find it (like behind the closet or in a box closed 364 days a year, etc. This is the reason why people have taken to doing “spring cleaning” in addition to Pesach cleaning. It is very important for those people to know the difference. I have spent the last 6 weeks really cleaning my house, throwing out a lot of stuff and getting more organized. Most of the year we’re just busy dealing with the day-to-day stuff, so these things get put to the back burner. Before Succos no one has time because it’s R’H and Y’K before, so Pesach works out to be a good time to deal with a lot of this stuff.
For families that have a lot of primarily small children, there is no way for them to tell the children to “clean up their room”. The mother has to do it. She obviously cannot clean everything at the same time, so some areas start earlier than others to give time to get to everything. The challenge then is to keep the children from undoing the work she already did by bringing their Purim treats, Shabbos snacks, etc, back into the rooms already clean. Kitchen is almost always saved for last, but that can also be start earlier just to keep the rhythm of the house on an even keel, especially if the mother is working and cannot do major Pesach all at one time plus keep her kids fed normal meals and have clean clothes available for the whole family.
As far as the meals, it says “ain simcha ela basar v’yayin” Chol Hamoed is really a YT day, just we are allowed to do things on it that we can’t do on Shabbos or YT, but we still are not allowed to degrade it. Most people have a custom and perhaps it is actually halacha (the more knowledgeable people here in the CR will probably clarify) to have a festive meal, like you would on Shabbos or YT, on Chol Hamoed. If you only eat salad and a main dish and one side on Shabbos, then you’re good to go with what you suggested. Many people even wash twice a day during Chol Hamoed. Since family is together a lot during the whole YT, more fancy sitdown meals are very customary. Many people buy only the bare basic products from the stores, like sugar, oil, vinegar and such. EVERYTHING else is made by hand. I have a friend who makes her own potato starch. It takes much more time if you don’t even have “second-level” products that you can purchase from the store. We often have soup, a few salads (make big amount for YT and they last a day or two of Chol HaMoed), main dish with something on the side and dessert. I don’t think it’s too “unhealthy”. I’m lucky because I do buy things from the stores but things take much longer during Pesach due to not being familiar with where things are, etc, after having brought all of my Pesach pots/dishes into the kitchen.
I hope you enjoy your holiday.