Queries for UK visa for parents

[IndiaUK]

Hello Seniors,

I am planning to sponsor my parents in the UK. I am a British Citizen. My parents haven't visited the UK so far. My father is retired from State Govt.in India. I have already filled the application form & paid the fee including VFS fee for New Delhi.
After filling the application form, there is checklist downloaded, which indicates to attach as below:

1) Tour details / flight details / letter of invitation / evidence of sponsor's immigration status in the UK
Query: Do I need to attach flight tickets etc? Visa guidelines inform not to attach the flight ticket/travel insurance. Please guide, what needs to be attached. I'll attach the sponsor information without any issue.

2) Additional Information : Evidence of family members remaining in your home country whilst you travel.
Query: My father is retired & mother is home maker. I am the only son, settled in UK. I have 2 sisters, both are married & settled in their families.
How to satisfy this requirement. Appreciate the views please.

3) As advised on HO website, all documents need to be the originals, however sponsor original documents can be attached with only one application. Can I attach the self attested copies with other application & I can mention this in my sponsor letter?

Appreciate any guidance please.

IndiaUK