Some thoughts on the missing data issue, which I believe is more than just a 'front end' issue.
I believe (trust?) all PWS data that has been ingested by WU is still there and that the issue lies with the processing of that data (data retrieval and subsequent manipulation by algorithms to generate information). I say this on the basis that information that was missing on the new site was still being displayed on the old site (until it was decommissioned).
That the missing information from the monthly view in the new site appears somewhat random or erratic (eg different days missing for different users) suggests the issue is not purely front end - rather that there are issues with the retrieval of data for a particular PWS. In my case going back to May/June, I experienced large chunks of missing data in the detailed table for current day weather (eg missing wind direction values) that were being displayed correctly in the old site. More recently, there have been occasions when daily information that was being displayed correctly one day would the next day not be displayed.
While the monthly view graphs and table are not updating correctly (eg. my last update was 5 days ago), this behaviour is itself somewhat erratic, again suggesting data processing issues.
As such, I think the issue requires expertise beyond that of web site 'front end' design and implementation. And this is where I am holding my breath for WU - hopefully not for too long.