Dont apply after expiry date. Better apply in post or PEO from 19 - 21 march You should legally in UK for 4 yrs 11 months 2 days.. check in ukba site... "Please do not send us your application more than 28 days before you become eligible to apply. If you do, we may refuse your application with ...

Its normal for dependents. There will not be any acknowledgement.
Direct biometric letter followed with passport and other documents in 2 weeks time and a day or two with biometric.
I too received biometric today for my wife and kid.

I think you need to consult some solicitor. Many people are facing similar issue now due to decision date.