Also a feature would be great is to be able to get the signed hex transaction, then we would be able to push our own transactions and wouldn't have worry about bits of proof not working!
Actually it is possible already. In javascript console (Ctrl+Shift+J in most browsers) there's hex dump of signed transaction when it is prepared to broadcast. Copy&paste to
https://blockchain.info/pushtx works.
Of course that it is ugly workaround and I really hope it won't be necessary since we rebuild server side today.
a. there is some near abusive use of the service
b. a configuration change was made yesterday in an attempt to reduce race conditions that lead to problems a few times during last days, this change was not implemented consistently and lead to major disruption tonight. This is now corrected.
Services are back normal now and we work on addressing the race conditions.