I've been using SD cards, micro-SD cards and CF cards for over a decade. These things do wear out. I only go with "name brands" and US made, but still, they develop problems, and they literally wear out after perhaps 1000 uses, perhaps sooner. I never trust a single SD or CF card to work without fail. I always carry a spare card, and when shooting with a Canon DSLR, I make sure that the menu item that lets you "shoot without card" is not checked. That way if a card goes bad when I'm shooting, the camera will tell me and I can change to my back up card.

You should be aware that live view is never real time. There is always a delay. Sometimes it is imperceptible, sometimes it's not. If you are shooting action, such as sports, you should never use live view. However, as others have mentioned, it often comes in handy. Considering all the mirrorless cameras out there, about the only real advantage of a DSLR today is to look at an optical version of the frame you're about to shoot. If you find yourself often using live view, and are having acceptable results, consider saving money and buying mirrorless next time you're in the market for a new body. There is nothing wrong with your camera body, today, even if you use live view a lot. Of course, whenever shooting video with a DSLR, you must use live view. In your case, as a newbie, I'd be researching what lens to buy next, because your body is plenty good. Camera bodies come and go, good lenses are forever if you take care of them.

You should consider Pro Camera Repair in San Diego. They should replace a shutter for around $100 less, they have a quick turnaround, and they will actually communicate with you.

I'm guessing that all current Nikon Coolpix cameras can do panorama. My cell phone does panorama. As to tilt-shift, I have a Canon TS-E 24, but recommend that most people that want to use it instead perform the same function in Photoshop, After Effects, or likely many other imaging applications.

I understand your desire to stay with Nikon. I believe that their Coolpix W300 camera will suit your needs. Additionally, this little baby can go underwater to 100 ft. and survive a 7 ft. drop to a cement floor. It comes in your choice of 3 colors and sells on B&H for $387. Plus, you can write this expense off your taxes and carry this 8 oz. camera in your purse. Its lens goes from 24-120 (35mm equivalent), which is probably a wider zoom range than the camera you have. Yes, it shoots 4K video and can wirelessly send photos to your laptop. I believe that the camera's GPS feature would also be very helpful in your profession.