Passport app questions

I'm considering the Passport to replace my rapidly dying Xperia Pro (2011 Android, hardware keyboard.) with a new phone. The Priv should be an obvious choice, but it's a) expensive b) the keyboard is not landscape and c) for the price, there is insufficient guarantee of longevity. I'm also not happy about the lack of a removable battery, but I doubt I'm going to get my own way there.

I have questions :

It's very concerning that the Facebook client is not being updated by Blackberry, and doesn't bode well for the future of the OS. Still, nothing new there then.. I can see most people are using the web browser, which is how I'm currently accessing it myself; the modern FB client is too slow for my phone.

How integral is FB to the hub, and what limitations does the current state of the FB client place on it?

I see that some apps are limited by Google Play Services not being present, but that there are hacks for this. Is it possible to easily enable and disable the service, so as not to eat battery life?

What I need to run is :

Lots of IMAP mail, stored locally as well as remotely (shouldn't be a problem). I presume it supports push mail.
Facebook, lots of it.
Whatsapp (native BB client, so ok?)
Kik messenger (amazon app store. will it eat battery?)
Maps (built in)
PDF viewer (built in)
Twitter (built in ok?)
Kindle client (native)
FTP (native)
SSH (native)
Jabber (native)
UK National Rail Enquiries (there appears to be a native First Best Western app which may do what I want)

The difficult bits :

Skype - best to run Android?
Memrise (no idea on this, help!)
OS Mapfinder (import from Android?)
iPlayer - what's the situation for offline play here?
Some method of downloading web pages to be studied later - must be apps for this?

Ideally I'd also like Nethack, a comics reader, and an ebay app - but the ebay app isn't much cop on Android either, to be honest.

Thanks for any help. I like the idea of the hardware, but the software I'm more cautious about..