SET(O) form has the list of all documents you need to send
1:Can you please confirm if I employee 2 people for 12 months full time (30 hours per week), will this suffice the requirement for ILR ?
Yes as long as those were during the extension period
2: I got my initial Tier 1 visa on 03 April 2014 to 03 April 2017 and got my second visa approval on 15 September 2017, it took six months to get the second ext approved (can I consider the six months towards the 5 years).
Can i apply for my ILR in April 2019?
Yes
Advice is given based on my personal research and experience only. Do NOT contact me via private message for immigration advice