Swap between Tier 2 and Tier 2 Dependent

Hi all,

I have a question regarding concerns about swapping Tier 2 and Tier-2 dependent visas between partners.

I'm a Tier-2 general visa holder and my spouse is a Tier-2 dependent visa holder. My wife is applying for a Tier 2 general to switch over from dependent. I'm losing my certificate of sponsorship and would like to apply for Tier 2 dependent of my spouse if the spouse's Tier 2 visa application is successful. We can't apply both together due to personal circumstances.

Q1. Is there a maximum time limit between which I can apply for the Tier-2 dependent visa after spouse's Tier -2 general application is successful, considering I'm losing my Tier-2 general visa at any time and the countdown to exit the UK starts?
I mean will the 1 year cooling period be applicable to me in case I have to exit the country before the end date or I can apply for Tier-2 Dependent from India soon after to reenter UK as dependent without waiting for expiry of 1 year cooling period?

Q2. Spouse obviously has to goto home country to apply the Tier-2. Could I apply the Tier 2 dependent immediately whilst I'm in the UK and spouse hasn't entered the UK or have to wait for Tier 2 spouse to check into the country before starting any application.

Q3. Due to the Christmas holiday season will there be delays in Tier-2 VISA application from India?

Many thanks in advance for the experts to respond to the questions.