Answering the OP’s questions...
yes. These are belly guns. Unfortunately some times both belly's.
yes. POI is variable by muzzle rise at bullet exit. Pressure, velocity, types of Bullets, and grip on the gun can affect Where the hole ends up.
I played around with All types of these guns extensively back in the day and Lost interest because of the quality. I locked one in a vise and pulled the trigger with a string in developing smokeless rounds. Some of the experiments did in fact destroy the gun And could have caused injury. Ammo went through a metamorphosis in that time as an industry standard was loosely being developed. Confusing names, sizing difference And powder volume between lots Etc put everything in a not so intuitive way for the end user.
I hope this helps.
enjoy your hobby but be very careful.