Tier-1 extension queries

I believe easy enough for the Gurus to clarify.

1. My current leave on tier-1 general migrant is expiring on July 2015 but we are intending to go for extension quite early in 2014 (couple of months from now). Is it allowed? can I extend my leave so early?

2. Once renewed successfully, is the date of the new granted leave will be day when it is approved or the day of the expiry. Because ILR application will cease to exist on or after April 2018, if I am granted by new leave on July 2015, then it will be July 2018 expiry and hence I might fall into trap! Just wanted to be safe...

3. If we have a small baby, as long as we are not intending to take him out of country, there is no need to apply for his grant for leave along with our application correct? Let's say in this extension application, I and my wife will be applying in 2014 and then after getting our visa renewed, if there is a need to go to our home country, then we can seperately apply for his passport and visa for travel.. correct?

Please can you help me?

1. Yes
2. New leave will start from date of approval