The 2 channel limit is because the box doesn't know how fast your broadband is - the EE TV product doesn't currently have a way of treating every customer differently. e.g. on a slower connection, the TV channels could consume all the internet bandwidth and then customers would call the helpdesk to complain that the internet doesn't work on their computer. This may change in the future to better handle different connections, but not any time soon.
BBC don't allow programmes on their channels to be recorded, if your TV Box is operating in internet mode - this is their right, as it's their content and they control how it can be consumed. If your box is running in Aerial mode then the restrictions are removed (and also the box can record 4 aerial channels at the same time).
Recordings would work across seasons as long as the broadcasters chose to use the same recording IDs. They generally don't though, to prevent new episodes and re-runs being recorded from the same recording request. Other platforms have added logic to map between series, however YouView doesn't offer this.
