Visa Extension

[Folake28]

My current student visa runs out September 2013. I should complete my 10 years by July 2014.My husband is currently on a Tier 1 working visa which he'll renew September 2013.
Q1.) Can we both apply in the Uk together and if so would I loose the 10 years accrued and can I still file for my indefinite next year?
Q2.) Do I need to apply from Nigeria to go on his visa as a dependant and if so would I loose the 10 years accrued and can I still file for my indefinite next year?
Q3.) Should I consider extending my student visa by taking up a Phd so that my ten years can be complete and and I can file for my indefinite next year

Please help.

Thanks.