10 years ILR

Hi - This is really a good forum and I always wish and pray for all members for their success.
My case history as below:
2005 to 2009 work permit
2009 to 2011 student
2011 to 2013 post study visa
2013 to 2014 tier-2 visa
2014 to 2018 tier-4 visa
10 years going to complete in Oct 2015
My wife and kids
2006 to 2018 - dependant visa based on my visa (all time we applied all together)
10 years going to complete in May 2016
Please can you suggest us a practical and sound route for our ilr. My questions
when should I apply ilr (considering my wife and kids visa)?
when my wife and kids should apply dependant visa? Can they remain on current tier-4 dependant visa until May 2016, after my ilr application?
When they should apply their ilr? is it May 2016 or they can apply earlier if come under some transition arrangement (if any) being here since 2006.
Should I change my T-4 visa to T-2 visa before applying ilr if tier-2 visa is helpful to get ilr?
I will really appreciate your suggestions. We all a bit worried as we are coming near to ilr date,
Thanks in advance

Senior members
I always submit my visa application before visa expiry - with above history of a number of visa changes, what would you suggedt 1) is my ilr applicstion would be straight forward for PEO same day appointment or 2) should i send my alllication through post. I appreciate your reply to help me