Planned when WhatsApp gets revamped in 5.1

Fixed in upcoming v5.0.3

Please ensure your users all have Avatars and a username. This is fixed in v5.0.2

That's the idea. You can still do that at the moment but you'll have to find out the image URL used in the website then you can swap it for another image URL.

You can. Swipe left on an outgoing message and you'll see "Switch to SMS"

Fixed in v5.0.2

Is this with latest update v5.0.1? If so, can you please send me a screenshot.

Sounds like an interesting idea!

I wish I could, but I am a very busy person. Let alone, it took me 9 months to develop/release v5.0.