EEA3 and CSI

Questions on applying for LPR under EEA3 as a student:

Is CSI required for people who became students before 2011?

Is CSI required for Non EU students who entered under Tier 4 (who ordinarily dont need CSI because can access NHS)?

Is CSI required for the continuous 5 year period? (for example what if if you have gaps in coverage, or switched between student or other status?)

If CSI is required for 5 years continuous up to the point of application, and i cant document this unbroken coverage, then do i have to purchase it now and wait a whole 5 years before i can apply?

thanks

Don't create excessive threads on same topic. http://www.immigrationboards.com/eea-ro ... 88754.html