Tier 2 General extension

[vivekr11]

I am bit confused to find the tier 2 general application for my visa extension. Any experts to help me out..?

1. Which is preferred application mode- Paper / Online application- for by post service application.
2. In the new online application link, dependents also included with the main applicant..? Or dependents should apply separately in the online application..? or provide the online application link for main applicant and dependents please.
3.What is the current duration for the visa processing time for Tier 2 general if applied by post for extension..?
4. Any specific things to consider while applying for Tier 2 extension apart from COS..?

Thanks for your timely help in advance.

Regards
Vivek