Thank you.
For the Start date, my employer put the date as 21st feb 2013, which was the expiry date for my previous visa.
But it would be okay if you put the expiry date of your present visa or the day after. My employer applied for another employee recently for which the employer put the next date to the expiry date and was still okay . The employee has received the visa as well.
Regarding the Job Type, I do not know much about your job duties but I would think any one from the following will do. It is fine as long as it is from NVQ6 and includes few of your job duties (or similar). I doubt you can find exact matching Job title, type and duties. And they also say 'Example job Tasks' on the SOC pdf.
2133 IT specialist managers
2134 IT project and programme managers
2135 IT business analysts, architects and systems designers
2136 Programmers and software development professionals
2139 Information technology and telecommunications
Details you can look at (Pages 51- 54)
http://www.ukba.homeoffice.gov.uk/sitec ... orkers.pdf
But please make sure that you employer mentions atleast few similar job duties shown under the Job type while creating your COS online.
Also please consider that all the above advice are purely based on my understing and personal experience and I am not a legal or visa expert.
Hope this helps.
Good Luck