I agree with you, Ryu . Except for a few things, but we'll start with Beerus : Beerus was literally stated to be able to destroy everything, even when he was clearly outside the Time Nest and not affiliated with the Time Patrol at that age/timeline [ Battle of Gods ] . he linked that above a while ago, but i'll definitely give you the link if you didn't see it .
In DB , Ki can be used for special abilities , but also can be harnessed for physical attacks . His Ki as a Demon God [ Base Form Demon God ] allowed him to do all this, there isn't nothing indicating he couldn't, if very well could be his own arrogance. Besides, he didn't seem to care that the Time Nest was to be destroyed. Like mentioned, Demigra was stated to have completely control over everything ( While limiting himself to his Base Form. All his best feats and statements were implied to only be for his Base Form ) .
His Base stats would more than likely scale to his Reality Warping, in the same way Many Reality Warper's striking strength still scales to their RW . Both times in his base he threatened to recreate all of history, which in Xenoverse would be the Time Nest and the Scroll of Eternity . He did it in the easiest way possible.
Do keep in mind that Demigra , Beerus, and Future Warrior were the only ones implied to be capable of destroying the entirety of the Time Nest [ NOT warping it. Warping it enough would destroy it according to Chronoa's words , WoG, and Mira's incident with the endless time paradoxes ] .However, i do have a great problem with that. If that was the case then how come when Mira created an endless amount of time paradoxes, the Time Nest didn't implode ? Basically because of Chronoa's statement of every warping of time creates an timeline , and the satatement that if time was affected enough, it would destroy itself , yet it tanked a Multiversal Attack [ because Mira created an endless amount of time paradoxes ] basically back then in XV1 ! BASE Demigra having the level of power of one-shotting it in his heavily restricted form should be notable enough to scale . Keep in mind Base Demigra is the equivalent of SSG In Xenoverse, so obviously Beerus would be much greater than . Base Demigra. Here are the people who should scale [WIP] :
Demon God Demigra [ Post-Absorption of Toki-Toki ] : Had control of the entire Time Nest in his Base Form. Destroyed the Time Nest casually , which tanked Mira's Endless Time Paradoxes [ Which due to a timeline being created , and time paradoxes/time tampering are stated to harm the Time Nest/History numerous times , meaning it tanked Multiversal Levels of Power. ] . His FP Demon God form is as powerful as Beerus, and even stronger possibly when at his critical stage when amping himself with Dark Magic [ As in the files, he is unafraid of fighting Beerus when he doesn't amp himself with Dark Magic, and even believes that he can destroy him at his fullest ] . To compare, his base form is comparable to Goku as an SSG .
XV1 Future Warrior : Took on Beerus and even impressed him enough to let him fight Demigra. Fought Demigra's Base form , capable of casually destroying the Time Nest , that tanked Mira's Endless Time Paradoxes, essentially tanking High-End Multiversal Levels .
XV1 & XV2 Goku : Base form Goku is comparable with Demigra's Base Form , due to fighting him well. His SSJ3 is able to hold off against Demigra's Final Form . As of XV2, he perfected his Godly powers, making him immensely stronger than back at that point in time, especially as an SSB - SSBKK .
XV2 Future Warrior : Harming Whis in BASE FORM during a Mentorship [ In Post-Story Mentorships, they show the full potential of the Xenoverse Main Protagonists. In XV2, they can't transformations, so all of their feats are in BASE. Whis is obviously is much much stronger than FP Demon God Demigra via a lot of reasons ] , taking on XV1 Future Warrior who was likely amped by Mira's Magic, albeit we don't know how much power he was given in comparison to others.
XV2 Final Form Mira : Fought XV2 SSB Goku , who through scaling is A LOT stronger than he was when he fought Demgira ( As in XV1, he had the God Power, but he didn't perfect it and train it like in XV2 ) . Base form Goku is comparable with Demigra's Base Form .