darrenay
You can send the ESA50 to your local Benefits Delivery Centre (BDC), the address should be on any of the correspondance you have received from the DWP. It is probably best to write a short covering letter which should be marked for the attention of the Decision Maker.
I am afraid that the Carers Allowance is only enabled through DLA MRC or HRC, there are no other "caring" benefits.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems