I know it's a tricky business. I've been there too. The key is to keep all device family and software at about the same generation to be cost effective at the same time they work each others without encountering "generation gaps".
No, you don't need. Likely the brand new FAP-21D comes with 1yr (or less, depending on when it went into the seller's inventory) support as well. You need to register it at their support web site and you can open a ticket with TAC in case any problems (regardless if you have support on the 30D or not. They're generous about that).
Just be aware the FAP with "-A" is for North America or Americas. It would most unlikely meet wireless regulations in France.