I'm using 3.5 with BB1 and 2 installed with no stability problems at all so far( knocks on wood)
Well, you don't have to install anything then. But this doesn't mean that the bugs are not there. It means that they just didn't happen to manifest on your setup.
are these updates/patches good for 3.5 too
If one of these updates/patches is not suitable for a specific AmigaOS version, i make it clear. Read IPrefs notes as an example for your OS.
Note: I have never used AOS 3.5. Only 3.1 and 3.9, that's why i'm not completely sure about it.