It's not particularly great with the Pi III either. I have one, and I find it's under powered for the "media server" role. Especially, if more than one person connects. I like it for lots of other things, but this isn't one of them.
Am I the only one though that uses the Pi with a (Synology) NAS with MySQL (MariaDB) to store the Kodi data, and my NAS (NFS) for the content? you can pick up where you left off from your Pi, to your laptop, or Phone.
I know...it's like Plex in architecture.
As for the remote, CEC will let you control Kodi from your TV's remote. Or if you have seperate audio, like a soundbar or AV receiver, a harmony remote will do.
No and that’s the issue. Works great for your local / NAS media. Lots of plugins for all sorts of things, except, Netflix, Amazon, XM. I still use the TV apps for that.
Wife and I use the Kore app. Less likely to forget where my phone is than a dedicated remote. Handy to have the youtube plugin and share a video to kodi from that app too.