Prob 1 – How are the other devices formatted? If they are NTFS they will not work with your MB, unless you install something like Paragon NTFS.
Prob 2 – You need to empty the recycle bin for it to be properly deleted and regain storage space.
Prob 3 – It’s something you have done/it’s broken
Prob 4 – It’s something you have done/it’s broken
Prob 5 – Settings > Displays Uncheck ‘automatically adjust brightness’ …or similar, my iMac has a diff setting to the portables.
Prob 6 – OS X can create PDFs. When you click on Print from the File menu or hit Command-P, look at the lower left corner of the print dialog box. You’ll see a menu called “PDF” click on the menu, and the first option you’ll see is “Save as PDF…”
Prob 7 – There is no prob 7, but reading the manual/Apple support pages may help for future reference.