The inner diameter of the ocular bell is not information provided by any rifle scope manufacturer. You will need to reach out to Riton directly for this information. Here is their contact information:
https://ritonoptics.com/contact-us/
Yes, The X1 primal 4-16x44 will hold zero on a 308 bolt action.
Email us at techsales@opticsplanet.com.
The scope takes a 1 inch diameter ring, but the actual height will be dependent on the platform you are mounting too. Please feel free to email us at techsales@opticsplanet.com with the make, model and caliber of firearm and we can make a ring recommendation based on that information.
Per Riton the scope has "Adjustment Range: 80 MOA"
Yes, the scope should have no issues with the recoil.
The scope can be used on just about any firearm platform including rimfire .22 LR.
Yes, the X1 Primal has a parallax adjustment of 10 yards to infinity.
That would be a question for Riton as they specifically state on their website that the eye relief is:
Eye Relief: 3.9in/100mm
The X1 Primal 4-16x44 has Japanese glass with a final assembly in China. We also finish the process with a dual quality control inspection in Tucson, AZ.