No, it will not as this unit requires an accessory rail for mounting.
It completely depends on the model of P22. If you have a P22 with the single accessory rail slot, it will likely not fit. If you have a newer model of the P22 with the multiple accessory rail slots, then it should fit one of the slots farther to the end of the frame.
Yes, this will fit the Walther CCP.
Yes, it will fit the S&W MP Shield 380 EZ.
No, there is not enough rail space to accommodate the TLR-7/TLR-8. You would be much better suited with something more compact like the TLR-3/TLR-4.
Unfortunately, the Streamlight TLR-8 Tactical C4 LED Weapon Light is no longer available for purchase. The XDM Elite OSP (3.8"/45ACP) uses a picatinny underside accessory rail and would be able to fit most compact lights designed for picatinny accessory rails. I would recommend the Streamlight TLR-8A Weapon Light and Laser, which can be found by using the link below:
https://www.opticsplanet.com/streamlight-tlr-8-a.html
Yes, the Streamlight TLR-8 Tactical C4 LED Weapon Light w/Laser Sight will fit and function as intended with the Glock 19X.
The Streamlight TLR-8 Tactical C4 LED Weapon Light w/Laser Sight at the link below will fit a Glock 48 MOS.
https://www.opticsplanet.com/streamlight-tlr-8-g-sub-for-glock-43x-48-mos-led-weapon-light-w-green-laser.html
Yes, the Streamlight TLR-8 Tactical C4 LED Weapon Light w/Laser Sight will mount to the underside accessory rail found on the Walther PPQ.
The Streamlight TLR-8 Tactical C4 LED Weapon Light w/Laser Sight will fit a Walther PDP Compact.