Questions about Metz 45 ct-1 flash light

hi, folks

i am planing to by an used Metz 45 CT-1 flash light. before that, i
get some questions about the gear,

1, i heard that the 45 CT-1 have a high volt that might damage some
morden cameras. i want to ask, if i buy a PC-hotshoe adapter, does the
problem still exist? i think that will damage the adapter at the worst,
am i right?

2, does the 45 CT-1 suitable to fill-in flash mode? in it's automatic
working mode, can i select any aperture on the dial? i means, if the
apertual used on the lens is X, can i set the aperture on the flash in
a way such as X - 1 - 1/3 stop?

3, how to test a used flash light, how can i believe it can still emit
enough and correct light?

thanks in advance.

-
woody