I am guessing you have a lot of videos purchased from/redeemed in iTunes? And it sounds like you don't want anything synced with google or to use google at all(e.g. contacts or calendar). If those are the constraints it does make it difficult.
In the US, I've found it pretty easy to mix and match (and it continues to get easier) - my family has a mix of Android, iPhones, iPads, Kindle Fire Tablets, Fire TVs, Roku, etc. Also, knowing that I was in mixed environment, I tried to pick services that support both devices.
For audio: I use Apple Music on my Android Phone (the latest beta even supports Android Auto) and I can cast it to a chromecast - and you can also side load Apple Music on Fire TV - and you can get 3rd party apps to cast the music from Android to AirPlay devices. Don't need to cast from Apple Music if you have and Apple TV. When I rip CDs, I rips to both FLAC and at the same time to Apple Lossless to sync with iTunes/Apple Music Cloud. I stream via DLNA server on PC if I want high quality streaming of my own collection (most of the time Apple Music is fine)
For mail/contacts/cal: I use gmail/google to sync contacts (on both Android and iPad/iPhone) - there are also ways to sync those between icloud and google if you want icloud to be the primary. Avoiding google, you can use Microsoft / outlook.com to sync across multiplatform (IOS/Android, etc). You can access icloud email from an Android mail app - I use gmail - my wife (only iphone/ipad) uses hotmail - my wife uses google to sync contacts and cal, but google for nothing else.
For video: I think video is probably hardest if you've got a lot invested and I think for UK you don't have all the same options yet; I am in US and I generally purchase/redeem video at Amazon (because it is now supported pretty broadly/cross platform on Android, IOS, FireTV, Apple TV) and at UltraViolet / Vudu if Amazon not available. Most movies in US (from Disney, WB, Sony, Fox, Universal) can be linked via Movies Anywhere to/from Apple, Amazon, Google, Vudu - so
For browser: I use chrome and sync to my Android Phone/iPad/PC/Mac, but you could use Firefox and do the same across IOS/Mac/PC/Android ...