All pretty typical issues with new RVs. Once you get the bugs all worked out you will certainly enjoy it more. The issue with your sewer pipe not lining up with the hole is the same for us, but ours is only off by just a tad so I don't have many issues getting the hose lined up. I may just take the Rotozip to the opening though and take out another 1/4" to make it easier.
I think there should be a disclaimer on RVs that says "Expect problems and if there are none you will be a happy camper right away, otherwise you will be in the same boat with all other new RV owners out there"
We just got ours back from the shop as the refrigerator failed 2 days before our last trip. We spent 10 days out using coolers and ice, what a pain. Fridge is fixed now. However I just noticed that my attempt to level up one of my slides has resulted in one end being about 3/8" lower the the other. Yep I'll be fixing that tomorrow.
Hang in there.