1) To add a new embed source, we need a sample of the embed code. You can open a support request requesting that it be added -- just give us the code for a sample embed. For security purposes, we have to be careful about what embeds we allow, so we might not be able to add it, but we do add everything we get a request for that we can.

2) Not 'complicated' so much as 'for long and boring reasons that would take me forever to explain, comments have to be held to a stricter security standard than entries', alas.