sorry your late for the party, bitcoing mining is for large companys which spend millions on asic miners and have access to near free geothermal electricty
Yes you can, I just ordered a 6500 and an MSI mobo to do it, you just need to install an older version of the bios here is a guide.
http://overclocking.guide/category/intel-oc-guides/skylake-non-k-oc/
see if your mobo is compatible
Well You can get a windows laptop if you are willing to sacrifice battery life and size / weight, The macbook air is as light as a typical school writing notebook.
Maybe get a used Razer blade?