Hey Patrick,
1)
Right, but more cpu power is faster loading.
2)
If you are gonna run os3.5 / os3.9 you would like some nice colors to go with that right? If you also take a high resolution e.g. interlaced screen, this wil cause a load on the cpu. It is very simple to check just open a drawer and you will see the icons coming up 1 at a time.
I'd say get a blizzard 030/50 with 16 or 32 meg simm on it. They don't cost much and are very stable with old software. Also faster a faster operating system.
If for some reason you would buy a 060, errors are bound to happen cause of the cpu instruction set. The 060 work fine with heavy programs and apps. There are some programs which could patch the workbench so it runs stable. But for games take the 030.
Greetz Henk