1, I'd wait a while, at least the first billing cycle.
2, no IP issue, as long as your receivers only connect from the same IP (network) you are fine (they can look for account splitters with receivers coming from multiple IPs). for example, I am in Michigan but my ISP IPs all show out of Wisconsin.
3, HD spot beams are tighter than SD ones, so if you had SD before HD may be more difficult. NYC is on a national beam but just the big 4 (abc, cbs, nbc, fox). The other networks are spot beamed.
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