Frieza CAN sense God Ki. He outright measures his energy in Golden relative to Goku's Blue form in the RoF arc. There is absolutely no denying this simple event. Other non-god ki users like Hit have measured Goku's Blue form before as well.
They do in-fact accept that Super Saiyan is at least a 40x multiplier.
https://vsbattles.com/vsbattles/2462932
The only source for UIO3 Goku > Beerus is a singular magazine scan which has no bearing on canon so that can't be used. You could argue that a suppressed Jiren was already considered stronger than a GoD but we have no actual confirmation of how strong Beerus actually is. Goku outright states that Broly is 'probably' stronger than Beerus and Beerus in the manga is shown to be capable of taking on several other GoDs with UIO.
You summarising Frieza's telekinesis as 'throwing rocks at someone' is laughable. Did you forget Frieza creating telekinetic spheres that trap his opponent? I also have to point to Chiaotzu who could completely freeze Krillin (despite being weaker) until his concentration was broken all the way into the middle of Pre-Z Dragon Ball.
Frieza has completely analyzed Goku's fighting style and has 100% awareness of how Instant Transmission works. He knows all of Goku's techniques, barring perhaps the Mafuba which Frost could easily deflect and requires equipment that Goku lacks. Ultra Instinct causes Goku's fighting style to change to be completely different according to Gohan but Frieza still understands every ability Goku has access to. And, again, Frieza's martial arts prowess was enough to handle Goku without Ki sensing abilities and without decades of martial arts experience.
So, overall the only two advantages Goku has here is the auto-dodging and his fighting style altering heavily from using UI. You could also argue his reactive evolution but I'm not convinced that isn't Goku just mastering the movements of UI. His offense is garbage in all forms but MUI which is a huge hindrance when Frieza is basically always going to be aiming to torture and kill Goku in any in-character match up.
So, again based on basic scaling presented in the show Frieza should be at least UIO2+ levels of power and could be argued to be UIO3 level in terms of his physicals. With UIO3 Goku having terrible offensive abilities (which basically means Frieza is going to tank Goku for hours on end).