I lived on Whidbey Island for a few months. It is beautiful, but a bit rural. There is not a lot to do there in the winter months (I was there February-April, but I hear winter is October-June or July pretty much), as almost everything is outside. I found it very isolating with an infant. All of the grocery stores on Whidbey are extremely expensive, and there are CSA's and produce delivery services in the area...again, expensive. I now live in Seattle and shop at Trader Joe's and the local farmer's markets, and my groceries are 1/2 as much as they were on Whidbey. The only big box store on the island is Wal Mart in Oak Harbor, and it is not a super Wal Mart. There is no mall, no Costco, no Target, etc. That all sounded GREAT to me until I was actually faced with the reality of driving 20 minutes to get ANYWHERE. Apparently there is a good community on South Whidbey, and I've heard wonderful things about the Waldorf school (I know a sweet mama down there I can introduce you too, if she doesn't stop by this thread.) I lived in Coupeville, and it was just way too out there for me. Oak Harbor has more stuff (La Leche league, one indoor play place, restaurants, etc), but still not a lot, and it's just kind of an icky place to me (it's a military town and young sailors + a rotating population and all of that). I love Langley and Freeland a lot, but they are expensive, and still not a lot of options as far as stores or activities, in my opinion. I think there are more mama's on South Whidbey, but since I was in the middle I didn't really meet a lot.
If you like to be outdoors, there are beaches and hiking trails and national parks galore. It's a very dog friendly place, if that is important to you. I found the political climate there to be pretty conservative, and surprisingly religious (at least, too religious for me) so I don't know how you feel about that.
Re: homebirth..there is a midwife on the island, and I've heard she is busy and books up, but I've also heard she is amazing. She is in Greenbank, I believe.
For doula/photography work, I'd worry a bit about being on the island just because there are only so many people having babies, and there is a large population of older people, retirees, etc, who are obviously not having babies. BUT, the midwife there is busy so maybe there would be enough work for you, I don't know! If you did need to go off island for a birth, and were on the south end, you'd take the ferry...in the middle of the night, it runs only once an hour, so you're looking at quite a commute before you could get to your client on the mainland.
The Clinton Waldorf school is starting up something in Mukilteo/Everett, I believe, which is just over the water from Whidbey. Mukilteo is in Snohomish county, and a beautiful little town which is a lot closer to activities and stores and things. There is also a large AP community in Snohomish county that I found it very easy to get assimilated within. It's also just a quick trip down to Seattle if you need it. I couldn't find a no-vax friendly pediatrician on Whidbey that took my insurance, but there's a great one in Snohomish County. We also love Mount Vernon and Burlington, which is just over Deception Pass from Whidbey Island. There is a large AP community and natural birth community there, as well, and it is a wonderful place to raise a family in my opinion! There's also a doula association in Mount Vernon that meets monthly, and things like Stroller Strides (mom/kid workout classes) and other things to do with kids. Now we live in NE Seattle and I love, love, love it here. I need to live in a walkable place so sadly Whidbey was not for me.
I only lived there a few months, but that is my take on Whidbey. I was SO excited to live rurally and be in the great outdoors and not depend on big box stores...but the reality was that I was pretty lonely, & long trips with a kid to the store or play groups or the library or whatever was just too exhausting for me. Maybe someone who has been there longer and has more resources in the area can give you more info.