For my money: I like all of the quint-for-permanence and quint-for-something-for-nothing house rules, but I'd also remove the Prime-2-to-borrow-local-quint effect. It's completely out of place for the sphere. Prime makes you able to get a lot more quint than other mages - so why does it also keep you from needing that quint? Plus it avoids characters that invest in a sphere for just one effect, like Time for hanging effects.

This makes quint much more valuable so a game with these rules would need some nodes. Or "alternative sources" (vampire vitae, werewolf caerns, ...