A: No. You need Custom Firmware (CFW) or HEN (Homebrew Enabler) to run backup ISOs.
A: Go to the r/Roms subreddit, look for their "Megathread," and navigate to the "Sony - PlayStation 3" section. They host compressed CHD and ISO files verified by the community. Ps3 Games Download High Quality Iso Highly Compressed
By using the sources and methods above, you can build a massive, high-fidelity PS3 library on a modest hard drive. Whether you are playing on original hardware with CFW or running 4K upscales on RPCS3, start with a compressed ISO—your bandwidth and SSD will thank you. look for their "Megathread