Both works. It has a builtin ARM based PC running SteamOS but it also comes with a 6GHz dongle allowing you to stream from your PC wirelessly.

The Steam Deck uses the capacitive thumb stick sensors to completely disable the trackpads as soon as the stick above the respective pad is touched. This works very well, so I think they‘ll implement the same thing here.

I don’t think this is quite right. CoD titles do take a long time to develop. They‘re just rotating studios, so they can achieve a yearly release cadence (the last six entries in the series had five different studios working on them). Also, they are by no means getting cheaper. According to court documents development costs rose from $450 million to over $700 million from 2015 to 2020 alone.