regarding 1)
This is kind of true. The dictionary was introduced by us (it is.a OH block) to allow passing parameters to other rules via a map. I only very late (but soon enough) noticed that there was a block missing that would be able to pick it up on the receiver rule side. So this is part of the release.
and then retrieving it via
However I guess what you are trying to do is
but there is no way of accessing this they keys from there. At least for the time being. Implementing such a block though is not a big deal and could be part of a next milestone release.
If this is not what you are looking for please be more specific what you expect.
regarding 2)
This should be the block you are looking for
see here and Event Object Attributesfor more details.
which generates the following code
logger.info(event.channel);