"1. A lot of spammy sites do not have any contact information, and no contact showing in the whois."
Mention that in the reconsideration request. Include a link to the whois page so that someone can see that the contact info is not listed.
"2. I am having to submit many of the requests via web forms so I can't actually keep evidence of what I have sent. Just keep a record which I am commenting on the disavow file. "
copy the URL of the page that the contact form appears on and (possibly) the confirmation URL page after you submit your request.
"4. The worst of it is I am seeing someone spammed hundreds of blogs with comment spam on one particular day with a link to my site. I doubt the SEO company would have done this so I believe it was the work of a competitor. MOst of the sites that the blog spam is on doesn't have a way to contact them."
Make sure to view those links and see if they are followed or nofollow. If they are nofollow, then I would imagine that you would have less to worry about. Usually blog comments are nofollowed by default in MANY (if not most) blog platforms.
~~~~ I am really sorry to hear it is taking a toll on you. I know it is taking a toll on me, too. But at the end of the day if your content is killer, then you could pack your bags and move to a new domain. It would suck big time, but it is like as they say, "Growing old sucks, but it is better than the alternative..."