Hello birminghamhc,
Thanks for reaching out to us!
This is definitely a strange issue to be having and I apologize for any inconveniences it may be causing.
For the 404 issues, have you tried re-saving your site’s permalinks ( “Settings” -> “Permalinks” and then clicking “save” while maintaining the current setup). This will allow your site to flush any rewrite rules that are in place and have them rewritten.
For the other issues, have you tried following the Testing for Conflicts procedures to see if there is a conflict with your current theme or any active plugins?
I’m sorry I wasn’t able to give you a direct response however I hope this was able to point you in the right direction.
Thanks!