WMZ,
There won't be any issue with the NRT connection, I've done it before from FUK with a similar layover so CTS shouldn't be an issue since both are same day domestic connections to NRT for ANA.
1984SW
There won't be a problem with the BKK-NRT-IAH legs. Might be an issue at IAH just because of the length of your layover and separate tickets. Worst case is you'll just have to recheck the bags with UA outside of Customs