Is the RTX 5070 wasted on a 1200p screen?

Not wasted, but underused. At 1920x1200 the GPU will push high frame rates in most games, and you can raise settings or use supersampling. The screen will not show the detail a higher-resolution panel would.

Is 64GB of RAM overkill for gaming?

For games alone, yes; 16GB to 32GB covers most titles. The extra memory pays off with virtual machines, large video projects, or dozens of browser tabs and apps open at once.

How does it compare with the ASUS TUF and ROG lines?

The V16 sits below the TUF and ROG families in build and cooling. Expect a plastic chassis and simpler thermal design, with the same class of CPU and GPU inside.

Can I upgrade the storage later?

Most ASUS 16-inch gaming laptops have an accessible M.2 slot, so a second SSD is usually possible. Check the service manual for your exact model before buying.