I know they are now code for most rooms in a house. Is it a good idea to
replace the "regular" circuit breakers in my home with arc faults? Is it ok
to install an arc fault on a GFCI circuit? I am thinking it might prevent a
fire someday in the future?
Do these things cause nusicence tripping when using a vacuum cleaner or
other sparking device?
I'd stay away from them for the time being because the technology was rushed
out and is not perfected. In new homes that are specifically wired for
arc-fault breakers they are ideal. But in older homes, light switches were
commonly wired on the outlet circuits. A switch can internally arc when
turning it off while under a load. This arc is enough to keep causing
nuisance tripping. Also, if you're the type to unplug something while it's
still on, the arc at the plug can also trip the breaker.
An arc-fault breaker can be used to power a GFI outlet. Keep in mind that if
you have a 3-wire circuit (2 hots, 1 neutral) such as with 12-3 or 14-3
homeruns to the panel, then you need a special arc-fault breaker that is
identified for common neutral use.