Tier 2 ICT Visa - Unpaid Leave & Long Term Sick Leave

Hi Team,

Could you help me with below queries.

Query1: On Tier2 ICT Visa category , In general Can an employee take Unpaid leave (apart from paid Annual leave) based on employers approval ? Is there any limit on number of days from UKBA ?

Situation1 : I am working in UK under Tier2 ICT Visa category for the past 8 plus years (from Dec'2010). Had baby in mid of 2018. After that was on Unpaid leave for next 6 months Nov 2018

Query2: Because of above mentioned unpaid leave for 6 months, will there be any complications from UKBA (or) HMRC since i was underpaid for that financial year ?
Query3: Does the employer/employee need to keep UKBA/HMRC updated regarding the Unpaid leave?
Query4: Will unpiad leave create any impact on Long residency application (after 10 years in Dec2020 )?

Situation2: After rejoining back to work in Dec 2018 , due to health complication had to go on Long term sicknessleave for another few months from Jan to March 2019
Note : In this case Statutory Sick pay was paid by employer

Query5: Does the employer/employee need to keep UKBA/HMRC updated regarding the Longterm sickness?
Query6: Will long term sickness leave create any impact on Long residency application (after 10 years in Dec2020 )?