Switching to Tier-2 from ICT Long term dependant

[KiranNarayan]

Hi,
My spouse is currently residing with me in the UK on ICT long-term dependent visa (valid until Feb2019) & now planning to switch to Tier-2 general visa category. We appreciate if anyone clarifies the below questions for us:
1) What specific type of Secured English Language Test - IELTS for UKVI is required to take up by my spouse if she opts for English language test instead of UK NARIC certificate?
2) What is the minimum score/grade is required in English language test with IELTS General to qualify to apply for Tier-2 general applicant?
3) Currently, she is working for a UK firm full time over a year. Does switching to Tier-2 general from ICT Dependent visa still require her to appear for Language test?
4) Does switching to Tier-2 general from ICT dependent still considered as a fresh application instead of considering a switch from existing ICT long term dependent visa?
Thanks,