So, it appears that you need the Gmail account for certain functionality, but there is nothing that says you have to use it as your main email address, contacts or calendar, or other functions. With a little bit of work, (and a lot of patience) I'm not using Google for anything significant, unless I chose to use a particular service.
I am using DejaOffice for my Contacts, Calendar, Memos, etc., and using Companion Link to sync that to my PC running Palm Desktop. (Haven't found a good equivalent desktop app that I like.) I disabled sync to Google so my contacts, calendar,etc stay where I want them. If you are willing to work with the quirks, it does the job. I use the email addresses that I have with my main ISP, Comcast. I handle email via K-9 Mail which allows POP3 or IMAP syncing.
I also avoid as much as I can, storing any of my data 'in the cloud'. I know that limits some flexibility in accessing my data, and may be a bit paranoid. ALL the data on my phone is synced with my Windows PC via various apps. So if I loose the phone, I haven't lost any data.