Hi DoctahDeane. Welcome to the forum and congratulations on your decision to build a teardrop. You're about to have a whole lot of fun and meet a lot of great people.
You are dealing with the same concerns that probably most of us had in the beginning. I didn't have a clue and questioned myself all along the way, but here I am and my teardrop works great, looks pretty nice, and doesn't leak at all. There were challenges getting to this point. The hatch was particularly challenging. If you're interested you can check out my build journal. Maybe you'll see something that will save you some money, work or anguish along the way.
I will say I did spend far more than I needed too for a number of reasons; choosing construction methods that were way more complicated than they needed to be (and overbuilding....lots of people do it), from changes (buying parts and materials ahead of time to do things one way and then changing my mind later), and from mistakes (usually as a result of one of the other two).
If there is any advice I can offer it is to keep your methods and materials as simple as you can while still accomplishing all of your objectives regarding appearance, structural integrity, and amenities.
Read a lot of build journals. Go to the hall of fame, finding teardrops that have some of the same qualities you are looking for and check out the builders site. Check out the galley gallery for lots of galley ideas. You will find everything there from simple and basic to absolutely opulent. There will be something there that seems to capture your style and they way you would like your galley to function. And then just have fun creating your perfect teardrop.
And speaking of build journals....please start one and include lots of

because we love them and the newbies that come behind you will appreciate the opportunity to learn from your journey.