I really like the corsair 600t but worried about working on it without touching a metal part of it since the whole thing is painted black as well as my psu.
Is there any way around this or am I worrying about nothing?
There is no need for concern. If anything, paint may reduce a metal's ability to transfer heat/electricity. When working on the interior of the machine, you should ground yourself by a wrist strap (which most of us fore go) or by touching the chassis; preferably an un-painted surface to discharge any static current you may be carrying.
And its true, a current that is too small too detect or feel is plenty to destroy components.