I've been away a little bit, so may be not so accurate.Check that crypto-map on each remote location includes in crypto ACL subnet for corresponding locations. I.e. crypto acl in Rackspace  should include ACL for subnet in Azure and vice versa. Then ...

Because 5505 doesn't support any kind of redundant interfaces and doesn't participate in STP, I assume that for link redundancy from your 5505 to stack of switches you can use cisco flex links technology, if your stack switches support it.Then you'd ...

I can't think of anything preventing you from using regular routing. Just make the subnet on the remote site reachable through the loopback interface and vice-versa.

Just to not to repeat what's been said million times, if you have newer 8.4+ version of ASA, this link should explain everything to you, begining from part where website is made available to the outside users. Replace webserver with your DVR and port...