BlueNav questions

I have a Meridian Color and was considering the BlueNav charts. Please
clarify a few things for me. When I buy the CD for N. America for
$125+/-, I activate it, I assume at no extra charge.

What exactly does this allow me to do? My understanding is that I must
give the serial# of my gps and the serial# of the SD card and the
software only works on this combination. Am I allowed only one chart,
period. Or is it only one chart at a time, i.e. write over one chart
with another. Of course I could pay extra for more charts, right? And
load them on the same SD card?

Can I load the BlueNav chart on the same SD card as MapSend Topo? Or
do I have to swap SD cards, one for BlueNav, one for Mapsend.

If I must get a dedicated card for BlueNav, What is the typical size
of a chart? What size card should I get?

And finally, will I be able to view all of the charts on the CD on my
computer prior to uploading them or must I just select by name?

Thanks,
Mike