Irving: Can't swim, unless there's some interplanetary adventure with a sea of mercury...
Won't kill, although there were two games in the campaign where he did-- both, notably, run by one guy who kept trying to do Iron Age scenarios despite our characters being more Silver Agey (well, kinda tarnished silver in Elizabeth's case). He tended to force the characters into "kill a few or let many die" situations; Irving tended to be very miserable after those.
Doesn't swear, but might use a rude word in a very matter-of-fact way if quoting dialogue, obnoxious lyrics, or suchlike. Admittedly, when he first awoke his memories were of earlier American English colloquialisms, and it was only sheer luck that one of the party members was able to inform him before a press conference that 'nigger' is NOT an acceptable term... ("But Huck called Jim that and they were friends... weren't they?")
Also, his very makeup tends to preclude certain situations-- being non-biological, he doesn't have the usual drives living beings do and can't be tempted by a lot of things.