But Humans don't do that ;p
Yes, I asked our developer to take a look into.
Q: How urgent & important those issues are for you?
About 1st "Search", I am not sure if we can help, Joomla loads module code twice, becuase of your choice. ALternative way would be to - disable Search input field from Mobile Menu, and put only Search link to Search component view. Then only one ID will be in HTML code. For users, it will be only one click more to make research.
About 2nd "Offanvas" - small php customization is needed.