For point no. 1,4G can also be used in lower bands like 700,800 and 1800.Most commonly used are no doubt above 2 Ghz,but this depends upon the availability of the spectrum in your country.So 4G in 800 or 1800 is not a bad choice.Actually there are 22 LTE FDD bands and 10 LTE TDD bands.FDD bands are paired and severl unpaired frequency allocations are being prepared for LTE TDD.
