woohoo! I might have to do the happy dance because I made it through this whole thread!
I have come up with some really random questions (some stupider than others) along the way.
1. Why do dogs have a little extra flap of skin at the lower corner of the ear? It is like a double layered little bit on only the bottom part of the ear. Am I making any sense?
We have that flap too, earlobes. Ours serve only as a place to wear earrings; the same flap on cats marks the place to tickle to make them twitch their ears.
2. Why does the ice from the ice-maker inside my freezer freeze all together in the catch-tray? Can this be prevented? It is a pain in the butt and I have actually broken catch-trays trying to dislodge enough ice to put in my water bottle.
Because it's a frost-free freezer. Those work by occasionally injecting warm air into the freezer, just enough to vaporize the frost but not enough to thaw the food. It IS enough to create a very thin film of water on your ice cubes. (It will also suck moisture out of imperfectly wrapped food, creating freezer burn.) As this thin film of water freezes again (and again, and again) it sticks the ice cubes together. Unless you are under severe water rationing, just dump the mass of stuck-together ice cubes into the sink once a week or so, just before you go to bed, and make sure the ice maker is on. Fresh ice in the morning! (If you ARE under severe water rationing, dump them into a bucket and use it to flush the toilet in the morning or something.)
4. When I tell my husband to keep the door shut so the flies won’t get in in the summer, he responds with "flies come from fruit". Is this accurate? (I am talking about the bigger flies with the red eyes which I believe are called "Blowflies" and not the little ones which I think are called "Drosophila/Fruit flies".
Does he think that the flies are spontaneously generated from the fruit?

That one was
disproved centuries ago! As PP have said, you let them in or bring in their eggs on things. Fruit fly eggs are all but invisible to the naked eye, so it's easier to do.
6. Why do I like to use a fork to put my dressing/dip on my salad/chips? I've had more weird looks for dipping my fork in my dressing before stabbing my salad than for using chopsticks to eat said salad. Am I just crazy?
Not at all! You get the taste of the dressing without consuming the calories of gobs and gobs of it. I tell DH that it's call 'dip' because you are supposed to insert the chips and then remove them, not use them as shovels to convey large quantities of dip to the mouth!
7. Would it damage a child to encourage them to be ambidextrous? Not trying to spark a flame war here, just wondering if I had children and encouraged them saying things like, "Ok, can you write that letter with your other hand too?" if it would scar them for life.
Forcing a child to use the non-dominant hand can cause things like stuttering, but I can't see how encouraging him to try it once in a while would hurt. Many children are ambidextrous naturally, but when schools get hold of them, they lose that ability. If you aren't strongly left-handed, teacher tells you to use your right hand to write, draw, throw a baseball, etc., and that ability gradually atrophies.
8. Is it possible to become ambidextrous as an adult? Ever since I injured my hand in high school, I've wondered if it would be a waste of time for me to try to train myself to write with both hands.
It can't hurt to try. I was one of those naturally ambidextrous kids, and over the last few years I've tried to regain as much of it as possible. Writing is still beyond me, though -- I mirror-write with my left hand!