Third time's a charm!
Lost my soul and won it all back.
I was thinking that the "Deal" had to do with the later games chances (more salvation and less damnation), but it appears to be random (unless it affects the deals, as well).
Meaning the less amount a deal is done, it's more likely to not be damned. and vice versa.
(Which if it's not that way, I think it would be more interesting if it was.)
Not using "Deal" - the only advantage it seems is getting a medal.