Hitman 3 was never released for the PlayStation Portable, meaning any "Hitman 3 PPSSPP ISO" files, including those from sites like isoroms.com, are fraudulent or modded, non-official files. Official, authentic Hitman titles, such as Blood Money — Reprisal, are available on the Google Play Store. For more information, visit Reddit r/PSP
Yes, unless you own a physical copy of the PSP game you are downloading and rip the ISO yourself using a modded PSP. Downloading from isoroms.com constitutes copyright infringement in the US and EU. Hitman 3 was never released for the PlayStation
Honestly? No.