Beyond 4K is absolutely the future for VFX heavy movies.
It will be a fun novelty I guess. $1500 for a toy is kinda eh but whatever.
Literally none of those solve this problem. You're trying to sound insightful or special by shitting on a relatively basic tool for correcting a lens. Shifting lenses have been used for decades for this specific instance but no, YOU have it really figured out.
You are completely wrong. This is the tool to do this correctly with in the first place. Correcting it would be fixing it in post. Distortion is a function of wide lenses. This is how you correct for it. There is no "better" way to fix this. This is how you handle that problem. You have no idea what you're talking about.
If you are doing this professionally, and are incorporated, you could get a small business loan from a bank if you have decent enough credit. Make sure it's going to be worth it. If it won't pay for itself in three years, you are taking on too much.
I don't understand this at all. It will never be as quick as knowing your keyboard shortcuts and having some practice with them. You can't map a full keyboards worth of controls to a touchscreen, and at that point it's just another keyboard. This will only slow you down, no matter which way you look at it.