1) ** Is it correct to follow “ease” with “at which” such as in “The **ease at which you can carry this bag depends on the angle you hold it from”
2) Does anyone have a good source recommendation for the rules of using different nouns with along with the word “which”?
ease at which is used fairly frequently in AmE as found here in Lloyd’s Penny Weekly Miscellany of Romance and General Interest – 1843 google book
The perfect ease at which Sir Skiffington evidently felt himself …
“The ease at which you can carry this bag depends on … “