"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."
Agitate it on occasion and it'll stop being so blocky. Also, if you find you don't use it up as fast as your freezer makes it, empty it on occasion to get rid of older ice. Ice will sublime, which means it'll evaporate directly from solid state over time. If you fill an ice tray and put it in your freezer for six months, the tray will be just about empty due to this. Old ice will give up a lot of dissolved air this way and so it'll shrink, deform, glue itself together and start to taste funny if you let it sit.
"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"."
Flies come from other flies, not fruit. Unless you buy your fruit with bugs or eggs already on board, flies won't spontaneously come into being from fruit. I thought this one got put to bed a century ago.
"5. Similarly, I was chewed out by my FIL for having a stack of old cereal boxes and pizza boxes stacked in the corner of the kitchen waiting for hubby to take them to the recycling center. FIL says that cockroaches come from having cardboard boxes around. Is this accurate? I worked fast food for years. There were never roaches around either the inside storage areas (freezer/refrigerator/dry-storage) where the food was stored in cardboard boxes or the dumpster where we disposed of said boxes whenever they were empty."
Cockroaches come from other cockroaches, not cardboard. That said, if you have conditions that draw cockroaches, they will take up residence in stacks of cardboard, so don't let it sit for too long and keep the food areas of your house clean so they don't show up to begin with.
"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 crazy, just unusual.
"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."
This would no more scar a child than telling them to practice piano, but if the child doesn't take to it then forcing said child to do something they hate to do isn't going to be very productive. As long as the child shows an interest in ambidexterity, I can't see where encouraging it would be a problem. The controversy sprung from the old practice of forcing left handed children to write with their right hand and the problems with writing that such a practice caused. Getting a child to write with both hands, for example, doesn't interfere with normal writing.
"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."
Insofar as it's possible for an adult to train themselves to do anything with motor function, it's possible. Of course, it's really up to you whether you feel it's worth the effort to learn to write with your other hand as opposed to other means of writing (like typing, for example). It's not an easy task but not harder than learning a dexterity sport or learning to play an instrument.
As a side note to writing with both hands, it's very likely that you already can write with your off hand, with the proviso that it won't be writing like you're accustomed to. To demonstrate, pick up a pen in each hand, and then write a normal sentence with your dominant hand, while writing the exact same sentence backwards with your off hand, working your hands toward or away from your body center at the same speed. Many people will find that the sentence written with the off hand will very closely resemble the dominant sentence when viewed in a mirror. Take note that you'll have to overcome that to learn to write normally with your off hand, and when you're done it's likely that your off hand handwriting will not match your dominant hand, to the point where you'll always have to sign your signature with your dominant hand or it won't match other samples.