Yes, this will fit the Hellcat.
It might fit on the Picatinny rail piece but is not a guarantee.
Yes, the correct models Viridian C5L Universal Sub-Compact ECR Laser w/ Tactical Light for your Glock 30sf are MPN:930-0006 (Green), and MPN:930-0001 (Red).
Yes, the Viridian C5L Universal Sub-Compact ECR Laser w/ Tactical Light will be compatible with the Walther P99. You will need to use the universal fit models MPN:930-0001 (Red), or MPN:930-0006 (Green).
Yes, the Viridian C5L Universal Sub-Compact ECR Laser w/ Tactical Light will be compatible with your PT 845. You will need to use the universal models designed for 1913 accessory rails MPN:930-0001 (Red), and MPN:930-0006 (Green). None of the models that include a holster would be compatible with your pistol.
The Viridian C5L Universal Sub-Compact ECR Laser should work for a Sig P365X Macro. You will need model 930-0001 or model 930-0006.
The Viridian C5L Universal Sub-Compact ECR Laser w/ Tactical Light will not fit the Glock 36 with the holster/light combo.
The Viridian C5L Universal Sub-Compact ECR Laser w/ Tactical Light that is compatible with the SR9C will also be compatible with the SR40C.
Yes, the correct Viridian C5L Universal Sub-Compact ECR Laser/light for your FN 509C would be MPN:930-0001 (Red), or MPN:930-0006 (green).
The Viridian C5L Universal Sub-Compact ECR Laser w/ Tactical Light will mount to picatinny accessory rails as well as other styles of handgun rails. So it will work with the Smith & Wesson 9mm EZ Shield.