Regarding the overlapping issue, you will need to set the row style to overflow hidden. Here is the snippet:

<AlternatingRowStyle CustomRules="overflow: hidden;" />
<RowStyle CustomRules="overflow: hidden;" />

The header misalignment has been submitted as a bug report to our developer. We will inform you if there is any update for this issue.

Hello Glenn,

Any updates regrading second issue? We are wating for positive reply from you on this.

Thanks,

G.S

Currently the bug status, header mislalignment in freeze column WebGrid, is still open and it is still being analyzed by our developer.

I just recieve an update on the header misalignment bug report, a fix will be available on the next hotfix release.