PR wishes to pursue higher studies in Europe \ Asia

[time2moveon]

Hello All,

Thanks to you all for hosting such a nice forum. It has helped every now and then in this GC journey.

I received my GC in Jan 2005. Now I am planning to go for higher studies in Europe or Asia. Hence I have few questions about residency and eligibility for Citizenship :
1) If I stay outside of US for 12-16 months, would the 5-year clock reset to zero?
2) Is it necessary to apply for a re-entry permit in this case??
3) If I keep visiting the US once in 6 months (using the re-entry permit or just the GC), would I be eligible to apply for citizenship in Jan 2009(completion of 5 years)??

Any feedback is appreciated.

Regards

[time2moveon]

Thanks ****.