Hi,
For the first issue, turning off the option I suggested should work for sure. If the checkboxes are unchecked, then nothing from those categories should appear. The query exclusions may conflict with that – I strongly recommend removing them, as those are not neccessary, the search will override either way.
Unfortunately I can’t tell if it is working okay only by looking at the front-end, as I can’t see the configuration, neither the category assignments. If you want, I can take a closer look via the administrator panel.
For the second query – that is not possible. The plugin can only filter one single posts widget at once. So only the one assignerd block will contain the results.