I know it's been a few months, but I thought I'd toss in my two cents. I certainly don't like anything going up me that doesn't need to be there. IMO, a doctor's hands aren't something that's necessary. My original view was that I'd have my midwife teach my husband how to check the dilation and just have him do the normal routine checks. The amazing woman not only is okay with it, but has already had other clients do the same thing. I'm currently 5 months pregnant and reading all those fun books and forums like this and finding out that it isn't that necessary, and can be harmful. I will probably have my husband check me at the start of labor and when I feel ready to push, but I'm still researching this. I actually researched this a little around a year ago and found this blog www.modernalternativemama.com/blog/2010/9/8/healthy-pregnancy-series-internal-exams.html (let me know if that doesn't work and I'll try it again) and she even mentioned checking the dilation on your own.
Now to answer your questions, Spiralshell, I'd highly suggest getting a friend you trust, or perhaps getting a doula to be with you to help you stand firm on your decision. The doctors can say all they want, but in the end, it IS your body. Actually, even before that, I'd suggest finding a good doctor/midwife you can trust. A home birth may not be an option, but what about a birthing center? Or perhaps find a midwife who works at a hospital. Or if you have to go to a normal doctor, I'd suggest interviewing a few with your birth plan up front, to see who would be a good candidate.
I haven't personally been there yet, but I've heard plenty of stories and I was at my nephew's birth. My SIL didn't want an epidural, but eventually caved when the doctor said she wasn't dilated enough. If I recall, she was at an 8 when she began to push and couldn't really stop. The doctor said it was too dangerous to push this early. Her DP couldn't help but feel agonized over watching her in such pain and it was hard for her to not push, so he asked what they could do to help her not push. The doctor suggested an epidural. DP asked SIL if she really wanted it, and she caved in.
I mentioned this concern to my midwife because I didn't want to feel the need to push too soon, and my midwife said she probably would have been fine pushing then. My SIL normally knows what she wants and will be insistent, but I believe the doctors caused her to second guess herself, and she didn't have anyone strong enough to say "No, you're fine, you don't need this, listen to your body and start pushing." (as a disclaimer, there could be a chance it would have been an issue, but I would rather trust a midwife's guidance than a doctor's agenda.) A few months ago, my SIL was the one to be with her best friend and when labor got too long and the woman said she just wanted the baby out of her, my SIL stepped in and said "no, you don't need anyone else to do this, you can do it" and guided her through the birth-- telling her when to relax, when to try and push, helping her feel comfortable through the labor, etc. If I ever had to go the route of a doctor I would definitely want my SIL to be there to make sure I didn't cave in when it was unnecessary.
(Also, perhaps interviewing a few midwives may also weaken your DP's resolve against a home birth, just a suggestion!)