Companies are welcome to stop increasing prices, but I'm not going to fall on my sword re salary negotiation to make a tiny contribution to stopping inflation.
I haven't tried it. The existing app works pretty well for my purposes, but I'll keep this in mind if that changes. I also have a Kindle, and the ReMarkable app is a much easier way to get content onto the device than the process you have to use to get non-Amazon content onto a Kindle. Just drag an drop, then it syncs.
I have one, thus far their cloud service is free and hopefully will continue to be so. Every ReMarkable comes with an 8gb cloud account, which is the same amount of storage on the device.
Hopefully this doesn't change, because it's really a pain to put things on the tablet without using their app.