In terms of per core & clock for clock, most probably yes. In MT however I expect 8 Zen cores to beat 4 SL/KL cores handily.Yes, but I guess that skylake will be for sure performing better than zen..
Anyway zen architecture will be on the new am4 socket.. So whatever I do sooner or later I should upgrade mobo
I'm only suggesting you hold onto your CPU/mobo for now because whatever happens with Zen you'll (almost) certainly have better price/perf next year, even with Intel CPUs & most certainly with AMD.