SGB - I think you are being a bit disingenuous about the studies regarding porn. I appreciate it suits your agenda to view porn as completely positive, but the truth is far more complex and nuanced and what's more, many, many women come on to Mumsnet and explain that their lives are being damaged by their partners use of internet porn. They deserve to be listened to and not lectured on your ideology.
Regarding peer-reviewd studies published, I would say that results are inconclusive (i.e. some find negative results; some positive). The largest study I could find (Grov, Gillespie, Royce and Lever, 2011, Archives of sexual behaviour, based on a survey of over 8,000 participants in 2004) found the negative aspects were that women were more likely to indicate they had less sex as a result of a partner's IP use, and men were more likely to indicate they were less aroused by real sex as a result of their own IP use. However, it also found that moderate or light amounts of IP use could provide benefits such as increases in the quality and frequency of sex, and increased intimacy with real partners. So we really can disgard all the black and white thinking now.
The most accurate interpretation would seem to be that internet pornography use does cause a problem for a certain percentage of users, especially where the use is heavy. Not really surprising - if you substituted the word alcohol for porn, the result would be the same.
So putting everyone's vested interests aside. Porn is causing a huge problem in this woman's marriage. Whether or not you think porn is disgusting or a bit of harmless fun is irrelevant. Her husband ignores her feelings about it and prefers it to having sex with her. I'd say she's got every right to feel agrieved and dissatisfied with the relationship and it's not really about the rights and wrongs of porn.
OP - personally, I think two suitcases of porn constitutes a heavy use, don't you? I am personally concerned that you are wiping the porn history off the laptop (not him?) when your dd has access. If you wish to stay with him, he should at least have his own password protected laptop for his 'hobby'.
I think the fact that he does not seem concerned about your sexual satisfaction and/or intimacy is a huge problem. Don't be told you are over-reacting.