Didn't bother, wanted a clean start anyway. Just grabbed a .txt for posterity but I'll probably delete that. BTW if you don't want WhatsApp images clogging up your gallery, you can go to the WhatsApp media folders and place a blank folder or file called .media and it will hide the media. https://www.whatsapp.com/faq/en/android/30031687.
Best way to migrate the contacts is to login to iCloud, select all the contacts and export the .vcf, then import that into Google and make sure your Google account syncs contacts.
There is an app to sync iCloud contacts but it just makes sense to move them over to your Google account.
Yeah I might just grab the txt of my chat history and email it to myself to store.
I followed your iCloud .vcf idea and it worked. But it didn't merge the contact pictures across? Do you know how I can get those? They came from Facebook originally as the app syncs with iOS contacts. Don't see a way of doing it in android?