I'm just wondering if this little gun will handle hot loads
Yes it will,but you should know,for your wifes sake,that the hot loads out of that light of a gun,will have substantial recoil compared to a pump or semi auto.
In a smooth bore,there are adapters made,that allow you to shoot several calibers of shot shells as well as rifle and pistol loads.
These little shotguns are damn near indestructible and easy to smith on yourself. unfortunately,H&R was bought out and they are no longer producing these shotguns rifles or slug guns.Its a shame because they really are a great gun.